Choices are, risk running an unpatched operating system with no security updates... - not a great idea if you're connecting to the internet with it.
Update to Windows 11. Can still be done even if you technically don't meet the minimum requirements, but probably only viable if it's not ridiculously old. I.e. I have a PC with a first gen Ryzen, and a Dell tiny PC hooked up to the TV that's 6th gen. They're probably candidates for that, although, for the Ryzen, I could just replace the processor.
Anything older than that, I've already replaced... But depending what you use it for..., Linux would work.