What Are You?

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Here's a quick way to tell whether a given machine is real or not: check the Win32_Baseboard class. You can use either Get-WmiObject or Get-CimInstance. Notice the results from a few physical machines.

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Now see the result when querying a Hyper-V virtual machine:

I don't have any VMware available so I don't know what kind of result that would show. I also haven't done extensive testing with items like a Microsoft Surface. I threw together this simple function you could use.

#requires -version 4.0

Function Test-IsVM {
[cmdletbinding()]
Param(
[Parameter(
 ValueFromPipeline,
 ValueFromPipelineByPropertyName,
 HelpMessage = "Enter the name of a computer")]
[ValidateNotNullorEmpty()]
[string]$Computername = $env:COMPUTERNAME
)

Begin {
    Write-Verbose "Starting: $($MyInvocation.Mycommand)"  
    $paramHash = @{
        ClassName = 'Win32_Baseboard'
        ErrorAction = 'Stop'
}
} #begin

Process {
    Write-Verbose "Querying $computername"
    Try {
        $paramHash.ComputerName = $Computername
        $data = Get-CimInstance @paramHash
        if ($data.Product -match "virtual") {
            $True
        }
        else {
            $False
        }
    }
    Catch {
      Write-Warning "$($computername.ToUpper()) : $($_.Exception.message)"
    }
} #process

End {
    Write-Verbose "Ending: $($MyInvocation.Mycommand)"
} #end

} #end function

Have fun.

Behind the PowerShell Pipeline

8 thoughts on “What Are You?”

    1. Thanks for the info. Is this from something running under VMware Workstation or a Vsphere server? In either case, it wouldn’t be hard to adjust the function to account for that product.

  2. You can see how to detect other people here: http://social.technet.microsoft.com/wiki/contents/articles/942.hyper-v-how-to-detect-if-a-computer-is-a-vm-using-script.aspx

  3. Checking the Model in the Win32_ComputerSystem class has always worked well for me. Good news is: Both are populated even back to Windows Server 2003 for those who still have to code for it.

  4. You can also get this information from the registry (in case of Hyper-V, don’t know about VM ware or other environments).
    $IsVM = Test-Path “HKLM:\SOFTWARE\Microsoft\Virtual Machine\Guest\Parameters”
    If($IsVM)
    {
    $VMHost = (Get-Item “HKLM:\SOFTWARE\Microsoft\Virtual Machine\Guest\Parameters”).GetValue(“HostName”)
    }

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