# WMI and CIM
# Querying objects
CIM/WMI is most commonly used to query information or configuration on a device. Thof 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.
CIM:
> Get-CimInstance -ClassName Win32_Process
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:
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.
CIM:
Get-CimInstance -ClassName Win32_Process -Filter "Name = 'powershell.exe'"
ProcessId Name           HandleCount WorkingSetSize VirtualSize  
--------- ----           ----------- -------------- -----------  
4800      powershell.exe 676         88305664       2199697199104
WMI:
Get-WmiObject -Class Win32_Process -Filter "Name = 'powershell.exe'"
...
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
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.
CIM:
Get-CimInstance -Query "SELECT * FROM Win32_Process WHERE Name = 'powershell.exe'"
ProcessId Name           HandleCount WorkingSetSize VirtualSize  
--------- ----           ----------- -------------- -----------  
4800      powershell.exe 673         88387584       2199696674816
Querying objects in a different namespace:
CIM:
> Get-CimInstance -Namespace "root/SecurityCenter2" -ClassName AntiVirusProduct
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:
> Get-WmiObject -Namespace "root\SecurityCenter2" -Class AntiVirusProduct
__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
# 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 righ 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.
CIM:
Get-CimClass
WMI:
Get-WmiObject -List
# Search for a class
You can search for specific classes using wildcards. Ex: Find classes containing the word process.
CIM:
> Get-CimClass -ClassName "*Process*"
   NameSpace: ROOT/CIMV2
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:
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.
CIM:
> Get-CimClass -Namespace "root/SecurityCenter2"   
   NameSpace: ROOT/SecurityCenter2
CimClassName                        CimClassMethods      CimClassProperties                                                           
------------                        ---------------      ------------------
....                                                   
AntiSpywareProduct                  {}                   {displayName, instanceGuid, pathToSignedProductExe, pathToSignedReportingE...
AntiVirusProduct                    {}                   {displayName, instanceGuid, pathToSignedProductExe, pathToSignedReportingE...
FirewallProduct                     {}                   {displayName, instanceGuid, pathToSignedProductExe, pathToSignedReportingE...
WMI:
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.
CIM:
> Get-CimInstance -Namespace "root" -ClassName "__Namespace"
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:
Get-WmiObject -List -Namespace "root"
# Remarks
# CIM vs WMI
As of PowerShell 3.0, there are two ways to work with management classes in PowerShell, WMI and CIM. PowerShell 1.0 and 2.0 only supported the WMI-module which is now superseeded by the new and improved CIM-module. In a later release of PowerShell, the WMI-cmdlets will be removed.
Comparison of CIM and WMI-modules:
| CIM-cmdlet | WMI-cmdlet | What it does | 
|---|---|---|
| Get-CimInstance | Get-WmiObject | Gets CIM/WMI-objects for a class | 
| Invoke-CimMethod | Invoke-WmiMethod | Invokes a CIM/WMI-class method | 
| Register-CimIndicationEvent | Register-WmiEvent | Registers event for a CIM/WMI-class | 
| Remove-CimInstance | Remove-WmiObject | Remove CIM/WMI-object | 
| Set-CimInstance | Set-WmiInstance | Updates/Saves CIM/WMI-object | 
| Get-CimAssociatedInstance | N/A | Get associated instances (linked object/classes) | 
| Get-CimClass | Get-WmiObject -List | List CIM/WMI-classes | 
| New-CimInstance | N/A | Create new CIM-object | 
| Get-CimSession | N/A | Lists CIM-sessions | 
| New-CimSession | N/A | Create new CIM-session | 
| New-CimSessionOption | N/A | Creates object with session options; protocol, encoding, disable encryption etc. (for use with New-CimSession) | 
| Remove-CimSession | N/A | Removes/Stops CIM-session | 
# Additional resources
Should I use CIM or WMI with Windows PowerShell? @ Hey, Scripting Guy! Blog (opens new window)