This has definitely been covered before, but it HAS been some time since Windows 10 was released, and it's safe to say that many have already tested it on older Macs. I currently have Windows 7 on my 4,1 Mac Pro. Any sense in upgrading to Windows 10? This partition is mostly for my Windows-only games, so if it improves performance, I might be interested. Some say they have had Windows 10 work fine on their machines; however, I am hesitant because others have had absolutely horrible issues with it. Is it worth upgrading (and getting rid of that "not genuine" badge I was presented with), or should I not try and fix what ain't broke?