Windows Management Instrumentation (WMI) provides a standardized interface for interacting with a Windows-based system regardless of the underlying hardware manufacturer and specific Windows version. WMI is a management framework that you can use to query a computer to determine its attributes. Computers running Windows XP and later versions of Windows support Windows Management Instrumentation (WMI). Working with WMI using Windows PowerShell is not that hard. In Windows PowerShell, you can use the Get-WMIObject cmdlet to get a WMI object that you want to work with. The basic syntax is

Get-wmiobject WMIclass

Get-wmiobject win32_logicaldisk

Get-wmiobject win32_Bios

The default namespace in Windows is root\CIMV2. In general, you’re not going to want to change this unless you have a very specific reason because all the WIN32_ classes fall into this namespace. The Get-WMIObject command you issued earlier all work because it just so happens that the WMI classes you queried all belong to root\CIMV2. If you want to query a class outside of this namespace, you need to explicitly define it using the -namespace parameter. The basic Syntax is

Get-WmiObject -Class WMIClass -Namespace NameSpace –ComputerName

                                 where
WMIClass is the WMI class you want to work with
NameSpace sets the namespace to use within WMI
ComputerName sets the name of the computer to work with

For Example:

Get-WMIObject –class IISWebService -namespace “root\MicrosoftIISV2” 

Get-WMIObject Win32_BIOS

Get-WMIObject –list

You can use WMI queries to examine settings based on just about any measurable characteristic of a computer, including

• Amount of memory installed
• Available hard disk space
• Processor type or speed
• Network adapter type or speed
• Operating system version, service pack level, or hot fix
• System services that are running
• Registry key or key value

You create WMI queries using the WMI Query Language. The basic syntax is

Select * from WMIObjectClass where Condition

In above syntax, WMIObjectClass is the WMI object class you want to work with, and Condition is the condition you want to evaluate. The Select statement returns objects of the specified class. A condition has three parts:

• The name of the object property you are examining
• An operator, such as = for equals, > for greater than, or < for less than
• The value to evaluate

 For example:

Get-WmiObject Win32_Service | Where-Object {($_.StartMode -eq “Auto”) -and ($_.State -ne “Running”)} | Select-Object DisplayName,Name,State

Get-WmiObject -query “Select * from Win32_Process where name=’notepad.exe’”

 Some of the more commonly used WMI classes are as follows