stopping MSI from launching an EXE in the SYSTEM context

On Error Resume Next
strComputer = "."
Set objWMIService = GetObject("winmgmts:" _
    & "{impersonationLevel=impersonate}!\" & strComputer & "rootcimv2")
Set colProcessList = objWMIService.ExecQuery _
    ("Select * from Win32_Process Where Name = 'BackgroundProcess.exe'")
For Each objProcess in colProcessList
    colProperties = objProcess.GetOwner(strNameOfUser,strUserDomain)
    If strNameOfUser = "SYSTEM" Then
        objProcess.Terminate()
    End If
Next