Win32_NTEventlogFile

The Win32_NTEventlogFile WMI classrepresents a logical file or directory of operating system events. The file is also known as the event log.

The Win32_NTEventlogFile WMI classrepresents a logical file or directory of operating system events. The file is also known as the event log.

Methods

Win32_NTEventlogFile has 16 methods:
Method Description
BackupEventLog Saves the specified event log to a backup file.
ChangeSecurityPermissions Class method that changes the security permissions for the logical file specified in the Name property.
ChangeSecurityPermissionsEx Class method that changes the security permissions for the logical file specified in the Name property.
ClearEventLog Clears the specified event log.
Compress Class method that compresses the logical file (or directory) specified in the Name property.
CompressEx Class method that uses NTFS compression to compress the logical file (or directory) specified in the Name property.
Copy Class method that copies the logical file or directory specified in the Name property to the location specified by the input parameter.
CopyEx Class method that copies the logical file or directory specified in the Name property to the location specified by the <em>FileName</em> parameter.
Delete Class method that deletes the logical file (or directory) specified in the Name property.
DeleteEx Class method that deletes the logical file (or directory) specified in the Name property.
GetEffectivePermission Class method that determines whether the caller has the aggregated permissions specified by the <em>Permission</em> argument not only on the file object, but on the share the file or directory resides on (if it is on a share).
Rename Class method that renames the logical file (or directory) specified in the Name property.
TakeOwnerShip Class method that obtains ownership of the logical file specified in the Name property.
TakeOwnerShipEx Class method that obtains ownership of the logical file specified in the Name property.
Uncompress Class method that uncompresses the logical file (or directory) specified in the Name property.
UncompressEx Class method that uncompresses the logical file (or directory) specified in the Name property.

Learn more about Invoke-CimMethod and how to invoke commands. Click any of the methods listed above to learn more about their purpose, parameters, and return value.

Properties

Win32_NTEventlogFile returns 39 properties:

'AccessMask','Archive','Caption','Compressed','CompressionMethod','CreationClassName',
'CreationDate','CSCreationClassName','CSName','Description','Drive','EightDotThreeFileName',
'Encrypted','EncryptionMethod','Extension','FileName','FileSize','FileType','FSCreationClassName',
'FSName','Hidden','InstallDate','InUseCount','LastAccessed','LastModified','LogfileName',
'Manufacturer','MaxFileSize','Name','NumberOfRecords','OverwriteOutDated','OverWritePolicy','Path',
'Readable','Sources','Status','System','Version','Writeable'

Unless explicitly marked as writeable, all properties are read-only. Read all properties for all instances:

Get-CimInstance -ClassName Win32_NTEventlogFile -Property *

Most WMI classes return one or more instances.

When Get-CimInstance returns no result, then apparently no instances of class Win32_NTEventlogFile exist. This is normal behavior.

Either the class is not implemented on your system (may be deprecated or due to missing drivers, i.e. CIM_VideoControllerResolution), or there are simply no physical representations of this class currently available (i.e. Win32_TapeDrive).

AccessMask

UINT32

Bitmask that represents the access rights required to access or perform specific operations on the event log file. For bit values, see File and Directory Access Rights Constants.

Note

On FAT volumes, the FULL_ACCESS value is returned instead, which indicates no security has been set on the object.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, AccessMask

Archive

BOOLEAN

If True, a file that contains Windows events should be archived.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Archive

Caption

STRING

Short description of the object.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Caption

Compressed

BOOLEAN

If True, a file that contains Windows events is compressed.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Compressed

CompressionMethod

STRING

Algorithm or tool used to compress the logical file that contains Windows events.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, CompressionMethod

CreationClassName

KEY PROPERTY STRING MAX 256 CHAR

Name of the first concrete class to appear in the inheritance chain used in the creation of an instance. When used with the other key properties of the class, this property allows all instances of this class and its subclasses to be uniquely identified.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name

CreationDate

DATETIME

Date that the file that contains Windows events was created.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, CreationDate

CSCreationClassName

STRING

Class of the computer system.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, CSCreationClassName

CSName

STRING

Name of the computer system.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, CSName

Description

STRING

Description of the object.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Description

Drive

STRING

Drive letter (including colon) of the file that contains Windows events.

Example: “C:”

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Drive

EightDotThreeFileName

STRING

DOS-compatible file name for the file that contains Windows events.

Example: “C:\PROGRA~1”

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, EightDotThreeFileName

Encrypted

BOOLEAN

File that contains Windows events is encrypted.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Encrypted

EncryptionMethod

STRING

Algorithm or tool used to encrypt the logical file.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, EncryptionMethod

Extension

STRING

File name extension (without the dot) of the file that contains Windows events.

Example: “txt”, “mof”, “mdb”

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Extension

FileName

STRING

File name (without extension) of the file that contains Windows events.

Example: “autoexec”

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, FileName

FileSize

UINT64

Size of the file that contains Windows events (in bytes).

For more information about using uint64 values in scripts, see Scripting in WMI.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, FileSize

FileType

STRING

File type (indicated by the Extension property).

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, FileType

FSCreationClassName

STRING

Class of the file system.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, FSCreationClassName

FSName

STRING

Name of the file system.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, FSName

Hidden

BOOLEAN

If True, a file that contains Windows events is hidden.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Hidden

InstallDate

DATETIME

Object is installed. This property does not need a value to indicate that the object is installed.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, InstallDate

InUseCount

UINT64

Number of “file opens” that are currently active against the file that contains Windows events.

For more information about using uint64 values in scripts, see Scripting in WMI.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, InUseCount

LastAccessed

DATETIME

Date and time that the file that contains Windows events was last accessed.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, LastAccessed

LastModified

DATETIME

Date and time that the file that contains Windows events was last modified.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, LastModified

LogfileName

STRING

Name of the file that contains Windows events. Standard log file names include: Application, System, and Security.

To return the actual path and file name of the event log (for example, C:\Windows\System32\Config\Sysevent.evt), use the Name property instead.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, LogfileName

Manufacturer

STRING.

Manufacturer from version resource, if one is present.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Manufacturer

MaxFileSize

WRITEABLE UINT32

Maximum size (in bytes) permitted for the file that contains Windows events. If the file exceeds its maximum size, its contents are moved to another file and the primary file is emptied. A value of zero indicates no size limit. WMI retrieves the Maxsize value from the Event Log Service registry values.

Although event logs can be sized as large as 4 gigabytes, in practice they should be limited to no more than 300 megabytes. Event logs larger than that can be difficult to analyze because of the number of events contained within the log and because event logs are not optimized for data retrieval.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, MaxFileSize

Name

KEY PROPERTY STRING

Inherited name that serves as a key of a logical file instance that contains Windows events within a file system. Full path names should be provided.

Example: “c:\winnt\system\win.ini”

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name

NumberOfRecords

UINT32

Number of records in the file that contains Windows events. This value is determined by calling the Windows function GetNumberOfEventLogRecords.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, NumberOfRecords

OverwriteOutDated

WRITEABLE UINT32 DAYS

Number of days after which an event can be overwritten.

Possible values for OverwriteOutDated include the following.

OverwriteOutDated returns a numeric value. To translate it into a meaningful text, use any of the following approaches:

Use a PowerShell Hashtable
$OverwriteOutDated_map = @{
Any record can be overwritten if necessary. If necessary, all existing events in the event log can be overwritten to make room for new events. = '0 (0x0)'
Events older than the specified number of days can be overwritten as needed. If the event log does not contain any records older than the value specified, no new events will be recorded until the log has been cleared. = '1 365'
No records can be overwritten. If the log reaches its maximum size, no new events will be recorded until the log has been cleared. = '4294967295 (0xFFFFFFFF)'
}
Use a switch statement
switch([int]$value)
{
  Any record can be overwritten if necessary. If necessary, all existing events in the event log can be overwritten to make room for new events. {'0 (0x0)'}
  Events older than the specified number of days can be overwritten as needed. If the event log does not contain any records older than the value specified, no new events will be recorded until the log has been cleared. {'1 365'}
  No records can be overwritten. If the log reaches its maximum size, no new events will be recorded until the log has been cleared. {'4294967295 (0xFFFFFFFF)'}
  default    {"$value"}
}
Use Enum structure
Enum EnumOverwriteOutDated
{
  _0_0x0                   = Any record can be overwritten if necessary. If necessary, all existing events in the event log can be overwritten to make room for new events.
  _1_365                   = Events older than the specified number of days can be overwritten as needed. If the event log does not contain any records older than the value specified, no new events will be recorded until the log has been cleared.
  _4294967295_0xFFFFFFFF   = No records can be overwritten. If the log reaches its maximum size, no new events will be recorded until the log has been cleared.
}

Examples

Use $OverwriteOutDated_map in a calculated property for Select-Object
<# 
  this example uses a hashtable to translate raw numeric values for 
  property "OverwriteOutDated" to friendly text

  Note: to use other properties than "OverwriteOutDated", look up the appropriate 
  translation hashtable for the property you would like to use instead.
#>

#region define hashtable to translate raw values to friendly text

# Please note: this hashtable is specific for property "OverwriteOutDated" 
# to translate other properties, use their translation table instead
$OverwriteOutDated_map = @{
Any record can be overwritten if necessary. If necessary, all existing events in the event log can be overwritten to make room for new events. = '0 (0x0)'
Events older than the specified number of days can be overwritten as needed. If the event log does not contain any records older than the value specified, no new events will be recorded until the log has been cleared. = '1 365'
No records can be overwritten. If the log reaches its maximum size, no new events will be recorded until the log has been cleared. = '4294967295 (0xFFFFFFFF)'
}

#endregion define hashtable

#region define calculated property (to be used with Select-Object)

<#
  a calculated property is defined by a hashtable with keys "Name" and "Expression"
  "Name" defines the name of the property (in this example, it is "OverwriteOutDated", but you can rename it to anything else)
  "Expression" defines a scriptblock that calculates the content of this property
  in this example, the scriptblock uses the hashtable defined earlier to translate each numeric
  value to its friendly text counterpart:
#>
 
$OverwriteOutDated = @{
  Name = 'OverwriteOutDated'
  Expression = {
    # property is an array, so process all values
    $value = $_.OverwriteOutDated
    $OverwriteOutDated_map[[int]$value]
  }  
}
#endregion define calculated property

# retrieve the instances, and output the properties "Caption" and "OverwriteOutDated". The latter
# is defined by the hashtable in $OverwriteOutDated: 
Get-CimInstance -Class Win32_NTEventlogFile | Select-Object -Property Caption, $OverwriteOutDated

# ...or dump content of property OverwriteOutDated:
$friendlyValues = Get-CimInstance -Class Win32_NTEventlogFile | 
    Select-Object -Property $OverwriteOutDated |
    Select-Object -ExpandProperty OverwriteOutDated

# output values
$friendlyValues

# output values as comma separated list
$friendlyValues -join ', '

# output values as bullet list
$friendlyValues | ForEach-Object { "- $_" }
Use $OverwriteOutDated_map to directly translate raw values from an instance
<# 
  this example uses a hashtable to manually translate raw numeric values 
  for property "Win32_NTEventlogFile" to friendly text. This approach is ideal when
  there is just one instance to work with.

  Note: to use other properties than "Win32_NTEventlogFile", look up the appropriate 
  translation hashtable for the property you would like to use instead.
#>

#region define hashtable to translate raw values to friendly text

# Please note: this hashtable is specific for property "Win32_NTEventlogFile" 
# to translate other properties, use their translation table instead
$OverwriteOutDated_map = @{
Any record can be overwritten if necessary. If necessary, all existing events in the event log can be overwritten to make room for new events. = '0 (0x0)'
Events older than the specified number of days can be overwritten as needed. If the event log does not contain any records older than the value specified, no new events will be recorded until the log has been cleared. = '1 365'
No records can be overwritten. If the log reaches its maximum size, no new events will be recorded until the log has been cleared. = '4294967295 (0xFFFFFFFF)'
}

#endregion define hashtable

# get one instance:
$instance = Get-CimInstance -Class Win32_NTEventlogFile | Select-Object -First 1

<#
  IMPORTANT: this example processes only one instance to illustrate
  the number-to-text translation. To process all instances, replace
  "Select-Object -First 1" with a "Foreach-Object" loop, and use
  the iterator variable $_ instead of $instance
#>

# query the property
$rawValue = $instance.OverwriteOutDated  

# translate raw value to friendly text:
$friendlyName = $OverwriteOutDated_map[[int]$rawValue]

# output value
$friendlyName
Use a switch statement inside a calculated property for Select-Object
<# 
  this example uses a switch clause to translate raw numeric 
  values for property "OverwriteOutDated" to friendly text. The switch
  clause is embedded into a calculated property so there is
  no need to refer to external variables for translation.

  Note: to use other properties than "OverwriteOutDated", look up the appropriate 
  translation switch clause for the property you would like to use instead.
#>

#region define calculated property (to be used with Select-Object)

<#
  a calculated property is defined by a hashtable with keys "Name" and "Expression"
  "Name" defines the name of the property (in this example, it is "OverwriteOutDated", but you can rename it to anything else)
  "Expression" defines a scriptblock that calculates the content of this property
  in this example, the scriptblock uses the hashtable defined earlier to translate each numeric
  value to its friendly text counterpart:
#>
 
$OverwriteOutDated = @{
  Name = 'OverwriteOutDated'
  Expression = {
    # property is an array, so process all values
    $value = $_.OverwriteOutDated
    
    switch([int]$value)
      {
        Any record can be overwritten if necessary. If necessary, all existing events in the event log can be overwritten to make room for new events. {'0 (0x0)'}
        Events older than the specified number of days can be overwritten as needed. If the event log does not contain any records older than the value specified, no new events will be recorded until the log has been cleared. {'1 365'}
        No records can be overwritten. If the log reaches its maximum size, no new events will be recorded until the log has been cleared. {'4294967295 (0xFFFFFFFF)'}
        default    {"$value"}
      }
      
  }  
}
#endregion define calculated property

# retrieve all instances...
Get-CimInstance -ClassName Win32_NTEventlogFile | 
  # ...and output properties "Caption" and "OverwriteOutDated". The latter is defined
  # by the hashtable in $OverwriteOutDated:
  Select-Object -Property Caption, $OverwriteOutDated
Use the Enum from above to auto-translate the code values
<# 
  this example translates raw values by means of type conversion
  the friendly names are defined as enumeration using the
  keyword "enum" (PowerShell 5 or better)
  
  The raw value(s) are translated to friendly text by 
  simply converting them into the enum type.
  
  Note: to use other properties than "Win32_NTEventlogFile", look up the appropriate 
  enum definition for the property you would like to use instead.
#>


#region define enum with value-to-text translation:
Enum EnumOverwriteOutDated
{
  _0_0x0                   = Any record can be overwritten if necessary. If necessary, all existing events in the event log can be overwritten to make room for new events.
  _1_365                   = Events older than the specified number of days can be overwritten as needed. If the event log does not contain any records older than the value specified, no new events will be recorded until the log has been cleared.
  _4294967295_0xFFFFFFFF   = No records can be overwritten. If the log reaches its maximum size, no new events will be recorded until the log has been cleared.
}

#endregion define enum

# get one instance:
$instance = Get-CimInstance -Class Win32_NTEventlogFile | Select-Object -First 1

<#
  IMPORTANT: this example processes only one instance to focus on
  the number-to-text type conversion. 
  
  To process all instances, replace   "Select-Object -First 1" 
  with a "Foreach-Object" loop, and use the iterator variable 
  $_ instead of $instance
#>

# query the property:
$rawValue = $instance.OverwriteOutDated

#region using strict type conversion

<#
  Note: strict type conversion fails if the raw value is 
  not defined by the enum. So if the list of allowable values
  was extended and the enum does not match the value,
  an exception is thrown
#>

# convert the property to the enum **OverwriteOutDated** 
[EnumOverwriteOutDated]$rawValue 

# get a comma-separated string:
[EnumOverwriteOutDated]$rawValue -join ',' 
#endregion

#region using operator "-as"

<#
  Note: the operator "-as" accepts values not defined
  by the enum and returns $null instead of throwing
  an exception
#>

$rawValue -as [EnumOverwriteOutDated]
#endregion

Enums must cover all possible values. If OverwriteOutDated returns a value that is not defined in the enum, an exception occurs. The exception reports the value that was missing in the enum. To fix, add the missing value to the enum.

OverWritePolicy

STRING

Current overwrite policy the Event Log service employs for this log file. Data can be never overwritten, or can be overwritten when necessary or when outdated. When data is outdated depends on the OverwriteOutDated value.

OverWritePolicy returns a numeric value. To translate it into a meaningful text, use any of the following approaches:

Use a PowerShell Hashtable
$OverWritePolicy_map = @{
The value of OverwriteOutDated equals 0 (zero). Any record can be overwritten to make room for new records. = 'WhenNeeded'
The value of OverwriteOutDated ranges from 1 to 365. Records older than a specified number of days can be overwritten to make room for new records. = 'OutDated'
The value of OverwriteOutDated equals 4294967295. Old records are never overwritten. = 'Never'
}
Use a switch statement
switch([int]$value)
{
  The value of OverwriteOutDated equals 0 (zero). Any record can be overwritten to make room for new records. {'WhenNeeded'}
  The value of OverwriteOutDated ranges from 1 to 365. Records older than a specified number of days can be overwritten to make room for new records. {'OutDated'}
  The value of OverwriteOutDated equals 4294967295. Old records are never overwritten. {'Never'}
  default    {"$value"}
}
Use Enum structure
Enum EnumOverWritePolicy
{
  WhenNeeded   = The value of OverwriteOutDated equals 0 (zero). Any record can be overwritten to make room for new records.
  OutDated     = The value of OverwriteOutDated ranges from 1 to 365. Records older than a specified number of days can be overwritten to make room for new records.
  Never        = The value of OverwriteOutDated equals 4294967295. Old records are never overwritten.
}

Examples

Use $OverWritePolicy_map in a calculated property for Select-Object
<# 
  this example uses a hashtable to translate raw numeric values for 
  property "OverWritePolicy" to friendly text

  Note: to use other properties than "OverWritePolicy", look up the appropriate 
  translation hashtable for the property you would like to use instead.
#>

#region define hashtable to translate raw values to friendly text

# Please note: this hashtable is specific for property "OverWritePolicy" 
# to translate other properties, use their translation table instead
$OverWritePolicy_map = @{
The value of OverwriteOutDated equals 0 (zero). Any record can be overwritten to make room for new records. = 'WhenNeeded'
The value of OverwriteOutDated ranges from 1 to 365. Records older than a specified number of days can be overwritten to make room for new records. = 'OutDated'
The value of OverwriteOutDated equals 4294967295. Old records are never overwritten. = 'Never'
}

#endregion define hashtable

#region define calculated property (to be used with Select-Object)

<#
  a calculated property is defined by a hashtable with keys "Name" and "Expression"
  "Name" defines the name of the property (in this example, it is "OverWritePolicy", but you can rename it to anything else)
  "Expression" defines a scriptblock that calculates the content of this property
  in this example, the scriptblock uses the hashtable defined earlier to translate each numeric
  value to its friendly text counterpart:
#>
 
$OverWritePolicy = @{
  Name = 'OverWritePolicy'
  Expression = {
    # property is an array, so process all values
    $value = $_.OverWritePolicy
    $OverWritePolicy_map[[int]$value]
  }  
}
#endregion define calculated property

# retrieve the instances, and output the properties "Caption" and "OverWritePolicy". The latter
# is defined by the hashtable in $OverWritePolicy: 
Get-CimInstance -Class Win32_NTEventlogFile | Select-Object -Property Caption, $OverWritePolicy

# ...or dump content of property OverWritePolicy:
$friendlyValues = Get-CimInstance -Class Win32_NTEventlogFile | 
    Select-Object -Property $OverWritePolicy |
    Select-Object -ExpandProperty OverWritePolicy

# output values
$friendlyValues

# output values as comma separated list
$friendlyValues -join ', '

# output values as bullet list
$friendlyValues | ForEach-Object { "- $_" }
Use $OverWritePolicy_map to directly translate raw values from an instance
<# 
  this example uses a hashtable to manually translate raw numeric values 
  for property "Win32_NTEventlogFile" to friendly text. This approach is ideal when
  there is just one instance to work with.

  Note: to use other properties than "Win32_NTEventlogFile", look up the appropriate 
  translation hashtable for the property you would like to use instead.
#>

#region define hashtable to translate raw values to friendly text

# Please note: this hashtable is specific for property "Win32_NTEventlogFile" 
# to translate other properties, use their translation table instead
$OverWritePolicy_map = @{
The value of OverwriteOutDated equals 0 (zero). Any record can be overwritten to make room for new records. = 'WhenNeeded'
The value of OverwriteOutDated ranges from 1 to 365. Records older than a specified number of days can be overwritten to make room for new records. = 'OutDated'
The value of OverwriteOutDated equals 4294967295. Old records are never overwritten. = 'Never'
}

#endregion define hashtable

# get one instance:
$instance = Get-CimInstance -Class Win32_NTEventlogFile | Select-Object -First 1

<#
  IMPORTANT: this example processes only one instance to illustrate
  the number-to-text translation. To process all instances, replace
  "Select-Object -First 1" with a "Foreach-Object" loop, and use
  the iterator variable $_ instead of $instance
#>

# query the property
$rawValue = $instance.OverWritePolicy  

# translate raw value to friendly text:
$friendlyName = $OverWritePolicy_map[[int]$rawValue]

# output value
$friendlyName
Use a switch statement inside a calculated property for Select-Object
<# 
  this example uses a switch clause to translate raw numeric 
  values for property "OverWritePolicy" to friendly text. The switch
  clause is embedded into a calculated property so there is
  no need to refer to external variables for translation.

  Note: to use other properties than "OverWritePolicy", look up the appropriate 
  translation switch clause for the property you would like to use instead.
#>

#region define calculated property (to be used with Select-Object)

<#
  a calculated property is defined by a hashtable with keys "Name" and "Expression"
  "Name" defines the name of the property (in this example, it is "OverWritePolicy", but you can rename it to anything else)
  "Expression" defines a scriptblock that calculates the content of this property
  in this example, the scriptblock uses the hashtable defined earlier to translate each numeric
  value to its friendly text counterpart:
#>
 
$OverWritePolicy = @{
  Name = 'OverWritePolicy'
  Expression = {
    # property is an array, so process all values
    $value = $_.OverWritePolicy
    
    switch([int]$value)
      {
        The value of OverwriteOutDated equals 0 (zero). Any record can be overwritten to make room for new records. {'WhenNeeded'}
        The value of OverwriteOutDated ranges from 1 to 365. Records older than a specified number of days can be overwritten to make room for new records. {'OutDated'}
        The value of OverwriteOutDated equals 4294967295. Old records are never overwritten. {'Never'}
        default    {"$value"}
      }
      
  }  
}
#endregion define calculated property

# retrieve all instances...
Get-CimInstance -ClassName Win32_NTEventlogFile | 
  # ...and output properties "Caption" and "OverWritePolicy". The latter is defined
  # by the hashtable in $OverWritePolicy:
  Select-Object -Property Caption, $OverWritePolicy
Use the Enum from above to auto-translate the code values
<# 
  this example translates raw values by means of type conversion
  the friendly names are defined as enumeration using the
  keyword "enum" (PowerShell 5 or better)
  
  The raw value(s) are translated to friendly text by 
  simply converting them into the enum type.
  
  Note: to use other properties than "Win32_NTEventlogFile", look up the appropriate 
  enum definition for the property you would like to use instead.
#>


#region define enum with value-to-text translation:
Enum EnumOverWritePolicy
{
  WhenNeeded   = The value of OverwriteOutDated equals 0 (zero). Any record can be overwritten to make room for new records.
  OutDated     = The value of OverwriteOutDated ranges from 1 to 365. Records older than a specified number of days can be overwritten to make room for new records.
  Never        = The value of OverwriteOutDated equals 4294967295. Old records are never overwritten.
}

#endregion define enum

# get one instance:
$instance = Get-CimInstance -Class Win32_NTEventlogFile | Select-Object -First 1

<#
  IMPORTANT: this example processes only one instance to focus on
  the number-to-text type conversion. 
  
  To process all instances, replace   "Select-Object -First 1" 
  with a "Foreach-Object" loop, and use the iterator variable 
  $_ instead of $instance
#>

# query the property:
$rawValue = $instance.OverWritePolicy

#region using strict type conversion

<#
  Note: strict type conversion fails if the raw value is 
  not defined by the enum. So if the list of allowable values
  was extended and the enum does not match the value,
  an exception is thrown
#>

# convert the property to the enum **OverWritePolicy** 
[EnumOverWritePolicy]$rawValue 

# get a comma-separated string:
[EnumOverWritePolicy]$rawValue -join ',' 
#endregion

#region using operator "-as"

<#
  Note: the operator "-as" accepts values not defined
  by the enum and returns $null instead of throwing
  an exception
#>

$rawValue -as [EnumOverWritePolicy]
#endregion

Enums must cover all possible values. If OverWritePolicy returns a value that is not defined in the enum, an exception occurs. The exception reports the value that was missing in the enum. To fix, add the missing value to the enum.

Path

STRING

Path of the file that contains Windows event. This includes leading and trailing backslashes.

Example: “\windows\system"

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Path

Readable

BOOLEAN

If True, a file that contains Windows events can be read.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Readable

Sources

STRING ARRAY

List of applications that are registered to log into this log file.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Sources

Status

STRING

Current status of an object. Various operational and nonoperational statuses can be defined. Available values:

$values = 'Degraded','Error','Lost Comm','No Contact','NonRecover','OK','Pred Fail','Service','Starting','Stopping','Stressed','Unknown'
Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Status

System

BOOLEAN

If True, a file that contains Windows event is a system file.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, System

Version

STRING

Version string from version resource if one is present.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Version

Writeable

BOOLEAN

If True, a file that contains Windows events can be written.

Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property CreationClassName, Name, Writeable

Examples

List all instances of Win32_NTEventlogFile
Get-CimInstance -ClassName Win32_NTEventlogFile

Learn more about Get-CimInstance and the deprecated Get-WmiObject.

View all properties
Get-CimInstance -ClassName Win32_NTEventlogFile -Property *
View key properties only
Get-CimInstance -ClassName Win32_NTEventlogFile -KeyOnly

Selecting Properties

To select only some properties, pipe the results to Select-Object -Property a,b,c with a comma-separated list of the properties you require. Wildcards are permitted.

Get-CimInstance always returns all properties but only retrieves the ones that you specify. All other properties are empty but still present. That’s why you need to pipe the results into Select-Object if you want to limit the visible properties, i.e. for reporting.

Selecting Properties

The code below lists all available properties. Remove the ones you do not need:

$properties = 'AccessMask',
              'Archive',
              'Caption',
              'Compressed',
              'CompressionMethod',
              'CreationClassName',
              'CreationDate',
              'CSCreationClassName',
              'CSName',
              'Description',
              'Drive',
              'EightDotThreeFileName',
              'Encrypted',
              'EncryptionMethod',
              'Extension',
              'FileName',
              'FileSize',
              'FileType',
              'FSCreationClassName',
              'FSName',
              'Hidden',
              'InstallDate',
              'InUseCount',
              'LastAccessed',
              'LastModified',
              'LogfileName',
              'Manufacturer',
              'MaxFileSize',
              'Name',
              'NumberOfRecords',
              'OverwriteOutDated',
              'OverWritePolicy',
              'Path',
              'Readable',
              'Sources',
              'Status',
              'System',
              'Version',
              'Writeable'
Get-CimInstance -ClassName Win32_NTEventlogFile | Select-Object -Property $properties
Limiting Network Bandwidth

If you work remotely, it makes sense to limit network bandwidth by filtering the properties on the server side, too:

Get-CimInstance -Class Win32_NTEventlogFile -Property $property | 
Select-Object -Property $property

Selecting Instances

To select some instances, use Get-CimInstance and a WMI Query. The wildcard character in WMI Queries is % (and not “*”).

The parameter -Filter runs a simple query.

Listing all instances where the property Caption starts with “A”
Get-CimInstance -Class Win32_NTEventlogFile -Filter 'Caption LIKE "a%"' 
Using a WQL Query

The parameter -Query uses a query similar to SQL and combines the parameters -Filter and -Property. This returns all instances where the property Caption starts with “A”, and returns the properties specified:

Get-CimInstance -Query "SELECT FSName, Readable, InUseCount, Caption FROM Win32_NTEventlogFile WHERE Caption LIKE 'a%'"

Any property you did not specify is still present but empty. You might need to use Select-Object to remove all unwanted properties:

Get-CimInstance -Query "SELECT FSName, Readable, InUseCount, Caption FROM Win32_NTEventlogFile WHERE Caption LIKE 'a%'" | Select-Object -Property FSName, Readable, InUseCount, Caption

Accessing Remote Computers

To access remote systems, you need to have proper permissions. User the parameter -ComputerName to access one or more remote systems.

Authenticating as Current User
# one or more computer names or IP addresses:
$list = 'server1', 'server2'

# authenticate with your current identity:
$result = Get-CimInstance -ClassName Win32_NTEventlogFile -ComputerName $list 
$result
Authenticating as Different User

Use a CIMSession object to authenticate with a new identity:

# one or more computer names or IP addresses:
$list = 'server1', 'server2'

# authenticate with a different identity:
$cred = Get-Credential -Message 'Authenticate to retrieve WMI information:'
$session = New-CimSession -ComputerName $list -Credential $cred

$result = Get-CimInstance Win32_NTEventlogFile -CimSession $session

# remove the session after use (if you do not plan to re-use it later)
Remove-CimSession -CimSession $session

$result

Learn more about accessing remote computers.

Requirements

To use Win32_NTEventlogFile, the following requirements apply:

PowerShell

Get-CimInstance was introduced with PowerShell Version 3.0, which in turn was introduced on clients with Windows 8 and on servers with Windows Server 2012.

If necessary, update Windows PowerShell to Windows PowerShell 5.1, or install PowerShell 7 side-by-side.

Operating System

Win32_NTEventlogFile was introduced on clients with Windows XP and on servers with Windows Server 2003.

Namespace

Win32_NTEventlogFile lives in the Namespace Root/CIMV2. This is the default namespace. There is no need to use the -Namespace parameter in Get-CimInstance.

Implementation

Win32_NTEventlogFile is implemented in Ntevt.dll and defined in Ntevt.mof. Both files are located in the folder C:\Windows\system32\wbem:

explorer $env:windir\system32\wbem
notepad $env:windir\system32\wbem\Ntevt.mof