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62. WMI and CIM

Note

The below information is extensively based in information taken from the PowerShell® Notes for Professionals book. I plan to extend this information based on my day to day usage of the language.

62.1: Querying objects

CIM/WMI is most commonly used to query information or configuration on a device. Through a class that represents a configuration, process, user etc. In PowerShell there are multiple ways to access these classes and instances, but the most common ways are by using the Get-CimInstance (CIM) or Get-WmiObject (WMI) cmdlets.

List all objects for CIM-class

You can list all instances of a class.

Version ≥ 3.0

CIM:

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Get-CimInstance -ClassName Win32_Process
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ProcessId Name HandleCount WorkingSetSize VirtualSize
--------- ---- ----------- -------------- -----------
0 System Idle Process 0 4096 65536
4 System 1459 32768 3563520
480 Secure System 0 3731456 0
484 smss.exe 52 372736 2199029891072
....
....

WMI:

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Get-WmiObject -Class Win32_Process

Using a filter

You can apply a filter to only get specific instances of a CIM/WMI-class. Filters are written using WQL (default) or CQL

(add -QueryDialect CQL). -Filter uses the WHERE-part of a full WQL/CQL-query.

Version ≥ 3.0

CIM:

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Get-CimInstance -ClassName Win32_Process -Filter "Name = 'powershell.exe'"
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ProcessId Name HandleCount WorkingSetSize VirtualSize
--------- ---- ----------- -------------- -----------
4800 powershell.exe 676 88305664 2199697199104

WMI:

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Get-WmiObject -Class Win32_Process -Filter "Name = 'powershell.exe'"
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...
Caption : powershell.exe
CommandLine : "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe"
CreationClassName : Win32_Process
CreationDate : 20160913184324.393887+ 120
CSCreationClassName : Win32_ComputerSystem
CSName : STACKOVERFLOW-PC
Description : powershell.exe
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ExecutablePath : C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
ExecutionState :
Handle : 4800
HandleCount : 673

Using a WQL-query:

You can also use a WQL/CQL-query to query and filter instances.

Version ≥ 3.0

CIM:

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Get-CimInstance -Query "SELECT * FROM Win32_Process WHERE Name = 'powershell.exe'"
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ProcessId Name HandleCount WorkingSetSize VirtualSize
--------- ---- ----------- -------------- -----------
4800 powershell.exe 673 88387584 2199696674816

Querying objects in a different namespace:

Version ≥ 3.0

CIM:

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Get-CimInstance -Namespace "root/SecurityCenter2" - ClassName AntiVirusProduct
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displayName : Windows Defender
instanceGuid : {D68DDC3A-831F-4fae-9E44-DA132C1ACF46}
pathToSignedProductExe : %ProgramFiles%\Windows Defender\MSASCui.exe
pathToSignedReportingExe : %ProgramFiles%\Windows Defender\MsMpeng.exe
productState : 397568
timestamp : Fri, 09 Sep 2016 21 : 26 : 41 GMT
PSComputerName :

WMI:

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Get-WmiObject -Namespace "root\SecurityCenter2" -Class AntiVirusProduct
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__GENUS : 2
__CLASS : AntiVirusProduct
__SUPERCLASS :
__DYNASTY : AntiVirusProduct
__RELPATH : AntiVirusProduct.instanceGuid="{D68DDC3A-831F-4fae-9E44-DA132C1ACF46}"
__PROPERTY_COUNT : 6
__DERIVATION : {}
__SERVER : STACKOVERFLOW-PC
__NAMESPACE : ROOT\SecurityCenter2
__PATH : \\STACKOVERFLOW-
PC\ROOT\SecurityCenter2:AntiVirusProduct.instanceGuid="{D68DDC3A-831F-4fae-9E44-DA132C1ACF46}"
displayName : Windows Defender
instanceGuid : {D68DDC3A-831F-4fae-9E44-DA132C1ACF46}
pathToSignedProductExe : %ProgramFiles%\Windows Defender\MSASCui.exe
pathToSignedReportingExe : %ProgramFiles%\Windows Defender\MsMpeng.exe
productState : 397568
timestamp : Fri, 09 Sep 2016 21 : 26 : 41 GMT
PSComputerName : STACKOVERFLOW-PC

62.2: Classes and namespaces

There are many classes available in CIM and WMI which are separated into multiple namespaces. The most common (and default) namespace in Windows is root/cimv2. To find the right class, it can useful to list all or search.

List available classes

You can list all available classes in the default namespace (root/cimv2) on a computer.

Version ≥ 3.0

CIM:

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Get-CimClass

WMI:

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Get-WmiObject -List

Search for a class

You can search for specific classes using wildcards. Ex: Find classes containing the word process.

Version ≥ 3.0

CIM:

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Get-CimClass -ClassName "*Process*"
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NameSpace: ROOT/CIMV2
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CimClassName CimClassMethods CimClassProperties
Win32_ProcessTrace {} {SECURITY_DESCRIPTOR, TIME_CREATED,
ParentProcessID, ProcessID...}
Win32_ProcessStartTrace {} {SECURITY_DESCRIPTOR, TIME_CREATED,
ParentProcessID, ProcessID...}
Win32_ProcessStopTrace {} {SECURITY_DESCRIPTOR, TIME_CREATED,
ParentProcessID, ProcessID...}
CIM_Process {} {Caption, Description, InstallDate, Name...}
Win32_Process {Create, Terminat... {Caption, Description, InstallDate,
Name...}
CIM_Processor {SetPowerState, R ... {Caption, Description, InstallDate,
Name...}
Win32_Processor {SetPowerState, R ... {Caption, Description, InstallDate,
Name...}
...

WMI:

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Get-WmiObject -List -Class "*Process*"

List classes in a different namespace

The root namespace is simply called root. You can list classes in another namespace using the -NameSpace parameter.

Version ≥ 3.0

CIM:

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Get-CimClass -Namespace "root/SecurityCenter2"
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NameSpace: ROOT/SecurityCenter2
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CimClassName CimClassMethods CimClassProperties
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------------ --------------- ------------------
....
AntiSpywareProduct {} {displayName, instanceGuid,
pathToSignedProductExe, pathToSignedReportingE...
AntiVirusProduct {} {displayName, instanceGuid,
pathToSignedProductExe, pathToSignedReportingE...
FirewallProduct {} {displayName, instanceGuid,
pathToSignedProductExe, pathToSignedReportingE...

WMI:

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Get-WmiObject -Class "__Namespace" -Namespace "root"

List available namespaces

To find available child-namespaces of root (or another namespace), query the objects in the __NAMESPACE-class for that namespace.

Version ≥ 3.0

CIM:

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Get-CimInstance -Namespace "root" - ClassName "__Namespace"
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Name PSComputerName
---- --------------
subscription
DEFAULT
CIMV2
msdtc
Cli
SECURITY
HyperVCluster
SecurityCenter2
RSOP
PEH
StandardCimv2
WMI
directory
Policy
virtualization
Interop
Hardware
ServiceModel
SecurityCenter
Microsoft
aspnet
Appv

WMI:

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Get-WmiObject -List -Namespace "root"