Software Deployment

First, thanks for such a reliable fource for information previously, this forum has been a big help. Now I'm finally registering and have an issue that I've been unable to solve on my own.

I have an MSI I will be deploying very shortly. Within this MSI I have a VB script that is not working when the MSI is executed in silent or passive mode (a must for deployment). When launching in the standard mode, given an interactive UI, everything works fine. Below is the script containing three 'simple' steps.

1. Kill process 'MDTAppPortal'
   1. This portion executes with no problem
2. Checks to ensure MDTAppPortal.exe has stopped running before continuing
   1. Again, as far as I can tell anyway, there are no problems executing
3. Uninstalls previous version of the application
   1. This portion simply does not execute if run quiet/passive
   2. no issues when run normal mode
   3. no issues when run as a .vbs external of the MSI

Can anyone give me insight as to why this isn't working and what can be done to correct it?

Dim objWMIService, objProcess, colProcess
Dim strComputer, strProcessKill
strComputer = "."
strProcessKill = "'MDTAppPortal.exe'"

Set objWMIService = GetObject("winmgmts:" _
& "{impersonationLevel=impersonate}!\\" _
& strComputer & "\root\cimv2")

Set colProcess = objWMIService.ExecQuery _
("Select * from Win32_Process Where Name = " & strProcessKill )
For Each objProcess in colProcess
objProcess.Terminate()

Next

WaitForProcess ".", "MDTAppPortal.exe"
Sub WaitForProcess(strComputer, strProcess)
Dim wmiQuery : wmiQuery = "Select * From Win32_Process Where Name='" _
& strProcess & "'"
Dim objWMIService : Set objWMIService = GetObject("winmgmts:\\" & strComputer _
& "\root\cimv2")
Dim colItems : Set colItems = objWMIService.ExecQuery(wmiQuery)

Dim intProcCount : intProcCount = colItems.Count
Do While intProcCount > 0
Set colItems = objWMIService.ExecQuery(wmiQuery)
intProcCount = colItems.Count
WScript.Sleep 1000
Loop
End Sub

Set colSoftware = objWMIService.ExecQuery _
("Select * from Win32_Product Where Name = 'MDT Application Portal'")

For Each objSoftware in colSoftware
objSoftware.Uninstall()
Next