Windows – How to debug PowerShell Scripts which are executed via GPO during startup

If you launch Powershell in an interactive "console" session, you will most likely be launching the 64-bit version of Powershell. (The executable will reside in Windows\System32.) You can also launch 32-bit Powershell from 64-bit Windows by executing the version that resides in Windows\SysWOW64. Make sure you know which version Task Scheduler is launching.

Keep in mind that each version of Powershell has a completely separate Execution-Policy. So you need to set the execution policy twice to cover both 32 bit and 64 bit versions of Powershell.

The snap-in you're attempting to load can also be critical. Some snap ins and COM objects can only be loaded in either a 32 bit or 64 bit environment. However, I just tested on a Server 2008 R2 server with PowerCLI installed and had no problems loading the snapin you referenced in both environments. So I don't think that's the issue here. But it's still something to consider. It might depend on that version of PowerCLI that you installed. Make sure that snapin loads from both 32 and 64 bit PS shells.

Finally, can you tell us exactly what the Action screen in your scheduled task says? What exact command line (w/ arguments) you're running? You might get more debug information if you run something like cmd /c powershell.exe c:\yourscript.ps1 2>&1> C:\debug.txt

It might also help to give us the output of Get-ExecutionPolicy -List from both 32 and 64-bit environments.

Also in your post you mention:

The task just continues to run perpetually. I don't get any result and it doesn't terminate.

That usually indicates it's waiting on user input.

Edit: Typos, typos eveyrwhere

I don't have any authoritative references, but the $HOME, $env:HOMEDRIVE and $env:HOMEPATH variables are user-specific environment variables.

It's unlikely that they would get assigned when you start a PowerShell host in the security context of the machine and not the user