Have a look at this topic: Tip: Troubleshooting ActionScript Command Lines (Windows). Specifically concentrate on whether you are running Powershell as 32bit and/or 64bit (it makes a massive difference for powershell scripts specifically and more so since the path to the module you are pointing to is x86/x64-redirected) and also, I would test whether the script itself works at all when ran by SYSTEM (instead of local user/session.
4 Likes