Hyper-V: How to Detect if a Computer is a VM Using Script

Article
1/17/2024

Sometimes you need to identify if something is running inside a Hyper-V virtual machine** before you take action. You can use this method: Determining If Hypervisor Is Installed, or Reporting the Identity of a Guest Operating System.

On a VM running on Hyper-V (and Virtual PC) , the Model property on the Win32_ComputerSystem class will return “Virtual Machine” and the “Manufacturer” will return “Microsoft Corporation”.

This sample VBScript uses the same logic found in the Microsoft Deployment Toolkit to show if a deployment is running in a VM.

If IsVM Then
    WScript.Quit 1
Else
    WScript.Quit 0
End If

Function IsVM

    ' Check the WMI information against known values

    bIsVM = false
    sVMPlatform = ""

    sMake = GetWmiPropertyValue("root\cimv2", "Win32_ComputerSystem", "Manufacturer")
    sModel = GetWmiPropertyValue("root\cimv2", "Win32_ComputerSystem", "Model")
    sBIOSVersion = GetWmiPropertyValue("root\cimv2", "Win32_BIOS", "Version")

    WScript.Echo "Manufacturer=" & sMake
    WScript.Echo "Model=" & sModel
    WScript.Echo "BIOSVersion=" & sBIOSVersion

    If sModel = "Virtual Machine" then

        ' Microsoft virtualization technology detected, assign defaults

        sVMPlatform = "Hyper-V"
        bIsVM = true

        ' Try to determine more specific values

        Select Case sBIOSVersion
        Case "VRTUAL - 1000831"
            bIsVM = true
            sVMPlatform = "Hyper-V 2008 Beta or RC0"
        Case "VRTUAL - 5000805", "BIOS Date: 05/05/08 20:35:56 Ver: 08.00.02"
            bIsVM = true
            sVMPlatform = "Hyper-V 2008 RTM"
        Case "VRTUAL - 3000919"
            bIsVM = true
            sVMPlatform = "Hyper-V 2008 R2"
        Case "A M I - 2000622"
            bIsVM = true
            sVMPlatform = "VS2005R2SP1 or VPC2007"
        Case "A M I - 9000520"
            bIsVM = true
            sVMPlatform = "VS2005R2"
        Case "A M I - 9000816", "A M I - 6000901"
            bIsVM = true
            sVMPlatform = "Windows Virtual PC"
        Case "A M I - 8000314"
            bIsVM = true
            sVMPlatform = "VS2005 or VPC2004"
        End Select

    ElseIf sModel = "VMware Virtual Platform" then

        ' VMware detected

        sVMPlatform = "VMware"
        bIsVM = true

    ElseIf sModel = "VirtualBox" then

        ' VirtualBox detected

        bIsVM = true
        sVMPlatform = "VirtualBox"

    Else
        ' This computer does not appear to be a virtual machine.
    End if

    ' Set the return value

    If bIsVM Then
        WScript.Echo "IsVirtualMachine=True"
        WScript.Echo "VirtualMachinePlatform=" & sVMPlatform
    Else
        WScript.Echo "IsVirtualMachine=False"
    End If

    IsVM = bIsVM

End Function

Function GetWmiPropertyValue(strNameSpace, strClassName, strPropertyName)

    On Error Resume Next

    strPropertyValue = ""
    set oWmiClass = getobject("winmgmts:" & strNameSpace).get(strClassName,&h20000) 'amended
    set oWmiProperties = oWmiClass.Properties_

    Set objWMIService = GetObject("winmgmts:\" & "." & "\ & strNameSpace)
    Set colItems = objWMIService.ExecQuery("Select * from " & strClassName,,48)

    For Each objItem in colItems
        For Each objProperty in oWmiProperties
            sLine = ""
            'WScript.Echo "- " & objProperty.name & ": " & strPropertyName

            If objProperty.Name = strPropertyName Then
                If objProperty.IsArray = True Then
                    sLine = "str" & objProperty.Name & " = Join(objItem." & objProperty.Name & ", " & Chr(34) & "," & Chr(34) & ")" & vbCrLf
                    sLine = sLine & "strPropertyValue = str" & objProperty.Name
                'ElseIf objProperty.CIMTYPE = 101 Then
                '    bHasDates = True
                '    sLine = "strPropertyValue = WMIDateStringToDate(objItem." & objProperty.Name & ")"
                Else
                    sLine = "strPropertyValue = objItem." & objProperty.Name
                End If

                'WScript.Echo sLine
                Execute sLine
            End If

        Next
    Next

    GetWmiPropertyValue = strPropertyValue

End Function

John Kelbley’s book Windows Server 2008 Hyper-V : Insiders Guide to Microsoft's Hypervisor, shares how you can use the root\CIM2 namespace and access the Baseboard class (full of interesting BIOS information) to get a description of the "physical" system. This class often includes information about the motherboard and chassis - manufacture, model, serial number, other. You can run the following VBS to get this info.

On Error Resume Next

Const wbemFlagReturnImmediately = &h10
Const wbemFlagForwardOnly = &h20

arrComputers = Array(".")
For Each strComputer In arrComputers
   WScript.Echo
   WScript.Echo "=========================================="
   WScript.Echo "Computer: " & strComputer
   WScript.Echo "=========================================="

*   Set objWMIService = GetObject("winmgmts:\" & strComputer & "\root\CIMV2")
   Set colItems = objWMIService.ExecQuery("SELECT * FROM Win32_BaseBoard", "WQL", _
                                          wbemFlagReturnImmediately + wbemFlagForwardOnly)*

*   For Each objItem In colItems
      WScript.Echo "Caption: " & objItem.Caption
      strConfigOptions = Join(objItem.ConfigOptions, ",")
         WScript.Echo "ConfigOptions: " & strConfigOptions
      WScript.Echo "   CreationClassName: " & objItem.CreationClassName
      WScript.Echo "         Description: " & objItem.Description
      WScript.Echo "        HostingBoard: " & objItem.HostingBoard
      WScript.Echo "         InstallDate: " & WMIDateStringToDate(objItem.InstallDate)
      WScript.Echo "        Manufacturer: " & objItem.Manufacturer
      WScript.Echo "               Model: " & objItem.Model
      WScript.Echo "                Name: " & objItem.Name
      WScript.Echo "OtherIdentifyingInfo: " & objItem.OtherIdentifyingInfo
      WScript.Echo "          PartNumber: " & objItem.PartNumber
      WScript.Echo "             Product: " & objItem.Product
      WScript.Echo "        SerialNumber: " & objItem.SerialNumber
      WScript.Echo "                 SKU: " & objItem.SKU
      WScript.Echo "              Status: " & objItem.Status
      WScript.Echo "                 Tag: " & objItem.Tag
      WScript.Echo "             Version: " & objItem.Version
      WScript.Echo
   Next
Next*

Function WMIDateStringToDate(dtmDate)
WScript.Echo dtm:
    WMIDateStringToDate = CDate(Mid(dtmDate, 5, 2) & "/" & _
    Mid(dtmDate, 7, 2) & "/" & Left(dtmDate, 4) _
    & " " & Mid (dtmDate, 9, 2) & ":" & Mid(dtmDate, 11, 2) & ":" & Mid(dtmDate,13, 2))
End Function

Here is a screen capture of the script results for a physical system running Windows Server 2008.

http://blogs.technet.com/blogfiles/tonyso/WindowsLiveWriter/HyperVHowToDetectifyouareinsideaVM_BA2E/image_thumb_1.png

NOTE the motherboard was manufactured by Intel (model DG45ID).

Running the same script in a virtual machine returns similar information, except on the virtual machine, the "motherboard" is shows as made by Microsoft (Microsoft does not make motherboards!) and is of a virtual type.

http://blogs.technet.com/blogfiles/tonyso/WindowsLiveWriter/HyperVHowToDetectifyouareinsideaVM_BA2E/image_thumb_2.png

The version number shown reflects the version of Hyper-V (Server 2008 RTM), and the Serial Number matches that found in the VM configuration file (XML file on the physical host).

The Perl script version for this is:

use strict;
use Win32::OLE('in');

use constant wbemFlagReturnImmediately => 0x10;
use constant wbemFlagForwardOnly => 0x20;

my @computers = (".");
foreach my $computer (@computers) {
   print "\n";
   print "==========================================\n";
   print "Computer: $computer\n";
   print "==========================================\n";

   my $objWMIService = Win32::OLE->GetObject("winmgmts:\\$computer\root\CIMV2") or die "WMI connection failed.\n";
   my $colItems = $objWMIService->ExecQuery("SELECT * FROM Win32_BaseBoard", "WQL",
                  wbemFlagReturnImmediately | wbemFlagForwardOnly);

   foreach my $objItem (in $colItems) {
      print "          Caption: $objItem->{Caption}\n";
      print "       ConfigOptions: " . join(",", (in $objItem->{ConfigOptions})) . "\n";
      print "   CreationClassName: $objItem->{CreationClassName}\n";
      print "         Description: $objItem->{Description}\n";
      print "        HostingBoard: $objItem->{HostingBoard}\n";
      print "         InstallDate: $objItem->{InstallDate}\n";
      print "        Manufacturer: $objItem->{Manufacturer}\n";
      print "               Model: $objItem->{Model}\n";
      print "                Name: $objItem->{Name}\n";
      print "OtherIdentifyingInfo: $objItem->{OtherIdentifyingInfo}\n";
      print "             Product: $objItem->{Product}\n";
      print "        SerialNumber: $objItem->{SerialNumber}\n";
      print "                 SKU: $objItem->{SKU}\n";
      print "              Status: $objItem->{Status}\n";
      print "                 Tag: $objItem->{Tag}\n";
      print "             Version: $objItem->{Version}\n";
      print "\n";
   }
}sub WMIDateStringToDate(strDate)
{
   return "blah";
}