Error when launching vbscript at windows startup

Question

I have a thin client running WES 7 Standard trying to launch a powerpoint file without loading the shell(explorer). I've done this with other applications like IE and Citrix Apps but am getting an error that I don't understand. Below is the script i'm using.
Set WshShell = Wscript.CreateObject("WScript.Shell")
CMD = "C:\slideshow.pptx /F"
strComputer = "."
WshShell.Run CMD,3,True
Do While (1)
Set objWMIService = GetObject("winmgmts:" _
& "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")
Set colProcesses = objWMIService.ExecQuery _
("Select * from Win32_Process Where Name = 'pptview.exe'")
If colProcesses.Count = 0 Then
WshShell.Run CMD,3,True
End If
Wscript.Sleep (2000)
Loop
I've tried various combinations in the CMD field for launching the file. These include using a batch file to pointing to powerpoint viewer and using the command line switches to launch file. Every method so far gives me error dialog from the viewer saying
there was an error accessing "the location of the powerpoint file." I have placed this file all over windows and get the same error and even tried this with an administrator account. I suspect it may have to do with the way I am launching this script
but do not understand why as I can launch it manually and it works no problem.
I launch the script by modifying the the HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Userinit key to point to a userinit.bat file.
@echo off
if not exist c:\%username%.lck goto Reg
Start c:\windows\system32\applaunch.vbs
exit
goto End
:Reg
start C:\WINDOWS\system32\userinit.exe
:End
Exit
Any ideas why I am getting this error? Any suggested alternatives? I am getting close to conceding and setting it up to launch after explorer loads because this particular machine and it's purpose won't be within easy reach of people accessing it but I do use
this method for other functions where we do not want explorer access available at all. i.e no start menu/taskbar loaded

Answer 1

What you are trying to do is not supported on Windows.
You mention a thin client.  This has nothing to do with thin clients.  Thin clients are just dumb monitors that run a remote RDP session.
If you are connecting to a terminal server there is a configuration in GP or in the terminal server configuration that let you specify an alternate shell.  If you are running this as a remote to a workstation then you need to specify the shell in the
user profile.  THis can be done through group policy or via a registry edit.
You cannot use a script for this and you cannot use an Office program without Explorer.  Office requires Explorer to run which is why you are getting that error.
Redirecting userinit for the whole machine will likely create many bad side effects as it is a fundamental process.  It is called multiple times during logon.  Replacing it with a batch file will cause you script to be executed multiple times. 
Usually userinit is called at least three times.  In a domain with Group Policy it can be called a dozen times.  I am pretty sure the only reason for it being in the registry is to allow for debugging.
Another this folder.ng to knowis that userinit has to complete before many things in Office will work correctly dependin on you implementation.
You can load the powerpoint viewer and directly launch that with the file name from the
"startup"  .  You can also try and set the powerpoint viewer as the alternate shell.  It just might work because it is designed to run completely stand alone with no Office and is used in kiosks which generally run without Explorer. 
You can also try to use IE to launch the ppt as it can host this with the viewer installed.  It can be set to fullscreen and it will re-launch  when exited just like Explorer does,
¯\_(ツ)_/¯