This question already has an answer here:
Windows PowerShell is a programming language, which is exactly what Stack Overflow is for. If you have a good question and show your research effort, your best bet will probably be SO.
Super User would work as well, as your question is about computers. I would recommend using Stack Overflow, though, because it's specifically for programming languages and there are about 64,000 questions tagged powershell, so it's definitely a well-covered topic.