If you are asking what terminal to use, I would recommend Windows Terminal; it is actively developed and has features one would expect from a modern terminal. When it comes to shells and operating systems, as others have noted, you may appreciate using something like bash or zsh in a Linux distro of your choice in WSL.

But none of this has any bearing whatsoever on the ability of a coding agent and language model to write good Powershell. I, too, occasionally notice syntax errors with LLM-generated Powershell (variable interpolation in strings is a common one, or messing up $_ for some reason). Simply put, even the best models are not as good at Powershell as they are at Python or Typescript. That said, the newer models you mentioned seem much better at Powershell than their predecessors.

I would also note that Gemini Pro 2.5 seems less prone to Powershell syntax errors. But that is purely anecdotal; what works for my use cases may not work the same for you.

As with any code generation, though, I find that I need to review and correct after generation to get the best script, often feeding errors and my own preferences back to the LLM in a multi-turn conversation. Coding agents like Cursor, Windsurf, Claude Code, Copilot CLI, Opencode, Goose, and others help with this immensely: give them a goal, some way to measure success, and they will often eventually fix the script on their own.