is a senior editor and author of Notepad , who has been covering all things Microsoft, PC, and tech for over 20 years. OpenAI released a new free and open GPT model yesterday that can run on a PC, and now Microsoft is making that easy to do for Windows users. The lightweight gpt-oss-20b model is now available on Windows AI Foundry, and will be coming soon to macOS, too. Microsoft’s speedy addition of OpenAI’s latest model to the Windows AI Foundry comes as Amazon was equally quick to adopt the new open-weight GPT-OSS models for its cloud services. It’s the first time you can run an OpenAI model locally on Windows, but it’s also the first time Microsoft’s biggest cloud competitor has had access to the latest OpenAI models — adding another dynamic to the complicated OpenAI and Microsoft partnership.