It's been awhile, I've set up dual boot systems in the past but it was adding XP with 7 or adding 10 to a win7 system. I have never done it with Windows 10 installed already as the start point. If I simply add XP to one of my non windows drives, won't that screw up the MBR on C:? Can I just physically unplug the C: (windows 10) and (other) drives and then install XP to my (current) D: drive, re-plug drives and fix the the boot menu with something like boot camp? Bad idea? Is there something easier? I'm doing it to play some older games that Windows 10 just outright refuses to run. I can't seem to find info on the web. All I could find was about adding 10 to an XP or 7 system.