Question

Using either VB.NET, C#, or VBScript, how can I check if the IIS 6 Management Compatibility feature and its subfeatures have been installed on a machine running IIS 7.x?

Answer 1

I performed some tests using a trial copy of Registry Workshop (the Compare Registries function) and found the following:

If IIS 7.x is installed, the following Registry key contains information about the installed subcomponents:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\InetStp\Components

Each installed feature is represented with a value of DWORD 0x00000001. If a feature is not installed, the value is missing.

For the Web Management Tools, the value names are as follows:

Web Management Tools
  IIS 6 Management Compatibility
    IIS 6 Management Console                              (LegacySnapin)
    IIS 6 Scripting Tools                                 (LegacyScripts)
    IIS 6 WMI Compatibility                               (WMICompatibility)
    IIS Metabase and IIS 6 configuration compatibility    (Metabase + ADSICompatibility)

  IIS Management Console                                  (ManagementConsole)
  IIS Management Scripts and Tools                        (ManagementScriptingTools)
  IIS Management Service                                  (AdminService)

Note that these component names came from a Windows 7 installation and might differ slightly from those of Windows Server 2008, though the Registry keys should be the same.

Some of this is mentioned in a note to this article:
Using Managed Code to Detect if IIS is Installed and ASP/ASP.NET is Registered

A list of these and other subcomponents can be found here:
Discover Installed Components

Update:

Some core functions from the final code. This is not the complete code but should be enough for anyone who spends the time looking up the component names for the various IIS versions:

Function IsIISComponentInstalled(ByVal ComponentName)
    Dim result
    Dim intProcessorArchitecture
    intProcessorArchitecture = GetProcessorArchitectureIIS()
    If intProcessorArchitecture = 64 Then
        '64-bit system
        On Error Resume Next
        Err.Clear
        result = RegReadDWORD(HKEY_LOCAL_MACHINE, "SOFTWARE\Microsoft\InetStp\Components", ComponentName, 64)
        If Err.Number <> 0 Then
            Err.Clear
            IsIISComponentInstalled = False
        Else
            If result = 1 Then
                IsIISComponentInstalled = True
            Else
                IsIISComponentInstalled = False
            End If
        End If
    Else
        '32-bit system
        If RegReadStringIIS("HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\InetStp\Components\" & ComponentName) = "1" Then
            IsIISComponentInstalled = True
        Else
            IsIISComponentInstalled = False
        End If
    End If

End Function

Function GetProcessorArchitectureIIS()
    Dim strProcessorArchitecture
    Dim oShell

    Set oShell = CreateObject("Wscript.Shell")
    strProcessorArchitecture = oShell.RegRead("HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Environment\PROCESSOR_ARCHITECTURE")

    If strProcessorArchitecture = "x86" Then
        GetProcessorArchitectureIIS = 32
    Else
        If strProcessorArchitecture = "AMD64" Then
            GetProcessorArchitectureIIS = 64
        Else
            GetProcessorArchitectureIIS = 0
        End If
    End If

End Function

Function RegReadStringIIS(sRegValue)
    Set oShell = CreateObject("WScript.Shell")
    On Error Resume Next
    RegReadStringIIS = oShell.RegRead(sRegValue)
    If Err Then
        RegReadStringIIS = ""
        Err.clear
    End If
    If VarType(RegReadStringIIS) < vbArray Then
        If RegReadStringIIS = sRegValue Then
            RegReadStringIIS = ""
        End If
    End If
    On Error Goto 0
End Function

'-------------------------------------------------------------------
' Reads a REG_SZ value from the local computer's registry using WMI.
' Parameters:
'   RootKey - The registry hive (see http://msdn.microsoft.com/en-us/library/aa390788(VS.85).aspx for a list of possible values).
'   Key - The key that contains the desired value.
'   Value - The value that you want to get.
'   RegType - The registry bitness: 32 or 64.
'
'References:
'   http://stackoverflow.com/questions/1229760/how-do-i-read-64-bit-registry-values-from-vbscript-running-as-a-an-msi-post-inst
'   http://msdn.microsoft.com/en-us/library/aa393067(VS.85).aspx
'   http://msdn.microsoft.com/en-us/library/windows/desktop/aa390445(v=VS.85).aspx
'
Function RegReadDWORD(RootKey, Key, Value, RegType)
    Dim oCtx, oLocator, oReg, oInParams, oOutParams
    Set oCtx = CreateObject("WbemScripting.SWbemNamedValueSet")
    oCtx.Add "__ProviderArchitecture", RegType
    Set oLocator = CreateObject("Wbemscripting.SWbemLocator")
    Set oReg = oLocator.ConnectServer("", "root\default", "", "", , , , oCtx).Get("StdRegProv")
    Set oInParams = oReg.Methods_("GetDWORDValue").InParameters
    oInParams.hDefKey = RootKey
    oInParams.sSubKeyName = Key
    oInParams.sValueName = Value
    Set oOutParams = oReg.ExecMethod_("GetDWORDValue", oInParams, , oCtx)
    RegReadDWORD = oOutParams.uValue
End Function