Collecting Information About Computers

Get-WmiObject is the most important cmdlet for general system management tasks. All critical subsystem settings are exposed through WMI. Furthermore, WMI treats data as objects that are in collections of one or more items. Because Windows PowerShell also works with objects and has a pipeline that allows you to treat single or multiple objects in the same way, generic WMI access allows you to perform some advanced tasks with very little work.

The following examples demonstrate how to collect specific information by using Get-WmiObject against an arbitrary computer. We specify the ComputerName parameter with the dot value (.), which represents the local computer. You can specify a name or IP address associated with any computer you can reach through WMI. To retrieve information about the local computer, you could omit the -ComputerName.

Listing Desktop Settings

We'll begin with a command that collects information about the desktops on the local computer.

Get-WmiObject -Class Win32_Desktop -ComputerName .

This returns information for all desktops, whether they are in use or not.


Information returned by some WMI classes can be very detailed, and often include metadata about the WMI class. Because most of these metadata properties have names that begin with a double underscore, you can filter the properties using Select-Object. Specify only properties that begin with alphabetic characters by using [a-z]* as the Property value. For example:

Get-WmiObject -Class Win32_Desktop -ComputerName . | Select-Object -Property [a-z]*

To filter out the metadata, use a pipeline operator (|) to send the results of the Get-WmiObject command to Select-Object -Property [a-z]*.

Listing BIOS Information

The WMI Win32_BIOS class returns fairly compact and complete information about the system BIOS on the local computer:

Get-WmiObject -Class Win32_BIOS -ComputerName .

Listing Processor Information

You can retrieve general processor information by using WMI's Win32_Processor class, although you will likely want to filter the information:

Get-WmiObject -Class Win32_Processor -ComputerName . | Select-Object -Property [a-z]*

For a generic description string of the processor family, you can just return the SystemType property:

PS> Get-WmiObject -Class Win32_ComputerSystem -ComputerName . | Select-Object -Property SystemType
X86-based PC

Listing Computer Manufacturer and Model

Computer model information is also available from Win32_ComputerSystem. The standard displayed output will not need any filtering to provide OEM data:

PS> Get-WmiObject -Class Win32_ComputerSystem
Domain              : WORKGROUP
Manufacturer        : Compaq Presario 06
Model               : DA243A-ABA 6415cl NA910
Name                : MyPC
PrimaryOwnerName    : Jane Doe
TotalPhysicalMemory : 804765696

Your output from commands such as this, which return information directly from some hardware, is only as good as the data you have. Some information is not correctly configured by hardware manufacturers and may therefore be unavailable.

Listing Installed Hotfixes

You can list all installed hotfixes by using Win32_QuickFixEngineering:

Get-WmiObject -Class Win32_QuickFixEngineering -ComputerName .

This class returns a list of hotfixes that looks like this:

Description         : Update for Windows XP (KB910437)
FixComments         : Update
HotFixID            : KB910437
Install Date        :
InstalledBy         : Administrator
InstalledOn         : 12/16/2005
Name                :
ServicePackInEffect : SP3
Status              :

For more succinct output, you may want to exclude some properties. Although you can use the Get-WmiObject's Property parameter to choose only the HotFixID, doing so will actually return more information, because all the metadata is displayed by default:

PS> Get-WmiObject -Class Win32_QuickFixEngineering -ComputerName . -Property HotFixID
HotFixID         : KB910437
__GENUS          : 2
__CLASS          : Win32_QuickFixEngineering
__DYNASTY        :
__RELPATH        :
__DERIVATION     : {}
__SERVER         :
__NAMESPACE      :
__PATH           :

The additional data is returned, because the Property parameter in Get-WmiObject restricts the properties returned from WMI class instances, not the object returned to Windows PowerShell. To reduce the output, use Select-Object:

PS> Get-WmiObject -Class Win32_QuickFixEngineering -ComputerName . -Property Hot
FixId | Select-Object -Property HotFixId

Listing Operating System Version Information

The Win32_OperatingSystem class properties include version and service pack information. You can explicitly select only these properties to get a version information summary from Win32_OperatingSystem:

Get-WmiObject -Class Win32_OperatingSystem -ComputerName . | Select-Object -Property BuildNumber,BuildType,OSType,ServicePackMajorVersion,ServicePackMinorVersion

You can also use wildcards with the Select-Object's Property parameter. Because all the properties beginning with either Build or ServicePack are important to use here, we can shorten this to the following form:

PS> Get-WmiObject -Class Win32_OperatingSystem -ComputerName . | Select-Object -Property Build*,OSType,ServicePack*

BuildNumber             : 2600
BuildType               : Uniprocessor Free
OSType                  : 18
ServicePackMajorVersion : 2
ServicePackMinorVersion : 0

Listing Local Users and Owner

Local general user information—number of licensed users, current number of users, and owner name—can be found with a selection of Win32_OperatingSystem properties. You can explicitly select the properties to display like this:

Get-WmiObject -Class Win32_OperatingSystem -ComputerName . | Select-Object -Property NumberOfLicensedUsers,NumberOfUsers,RegisteredUser

A more succinct version using wildcards is:

Get-WmiObject -Class Win32_OperatingSystem -ComputerName . | Select-Object -Property *user*

Getting Available Disk Space

To see the disk space and free space for local drives, you can use the WMI Win32_LogicalDisk class. You need to see only instances with a DriveType of 3—the value WMI uses for fixed hard disks.

Get-WmiObject -Class Win32_LogicalDisk -Filter "DriveType=3" -ComputerName .

DeviceID     : C:
DriveType    : 3
ProviderName :
FreeSpace    : 65541357568
Size         : 203912880128
VolumeName   : Local Disk

DeviceID     : Q:
DriveType    : 3
ProviderName :
FreeSpace    : 44298250240
Size         : 122934034432
VolumeName   : New Volume

Get-WmiObject -Class Win32_LogicalDisk -Filter "DriveType=3" -ComputerName . | Measure-Object -Property FreeSpace,Size -Sum | Select-Object -Property Property,Sum

Getting Logon Session Information

You can get general information about logon sessions associated with users through the WMI Win32_LogonSession class:

Get-WmiObject -Class Win32_LogonSession -ComputerName .

Getting the User Logged on to a Computer

You can display the user logged on to a particular computer system using Win32_ComputerSystem. This command returns only the user logged on to the system desktop:

Get-WmiObject -Class Win32_ComputerSystem -Property UserName -ComputerName .

Getting Local Time from a Computer

You can retrieve the current local time on a specific computer by using the WMI Win32_LocalTime class. Because this class by default displays all metadata, you may want to filter it using Select-Object:

PS> Get-WmiObject -Class Win32_LocalTime -ComputerName . | Select-Object -Property [a-z]*

Day          : 15
DayOfWeek    : 4
Hour         : 12
Milliseconds :
Minute       : 11
Month        : 6
Quarter      : 2
Second       : 52
WeekInMonth  : 3
Year         : 2006

Displaying Service Status

To view the status of all services on a specific computer, you can locally use the Get-Service cmdlet as mentioned earlier. For remote systems, you can use the WMI Win32_Service class. If you also use Select-Object to filter the results to Status, Name, and DisplayName, the output format will be almost identical to that from Get-Service:

Get-WmiObject -Class Win32_Service -ComputerName . | Select-Object -Property Status,Name,DisplayName

To allow the complete display of names for the occasional services with extremely long names, you may want to use Format-Table with the AutoSize and Wrap parameters, to optimize column width and allow long names to wrap instead of being truncated:

Get-WmiObject -Class Win32_Service -ComputerName . | Format-Table -Property Status,Name,DisplayName -AutoSize -Wrap