I haven't really looked through all the script but there doesn't seem to be anything wrong with it. I have a lot of work though, so you'll understand if I dont run unknown scripts for the sake of testing.

It won't be .NET, since it's separate to the command line utilities. The only thing that could be causing a problem, though I'm not sure is environment variables. Perhaps things like systemroot are not set on some people's machines or are different. Should probably take a look into the effects of the script in those cases.