Can you play a x-box game on a PC

Theoretically, any game can be played on a PC. But it seems to take a fair amount of time before any console gets ported to the PC. Latter generation consoles are not as available on the internet, and so far, there is no PC substitute in existence for any "living" console. So Xbox 360 is out. If by Xbox, you mean the original, then sure! There exist emulators for the Xbox original. I don't know if they can play disks, but they can surely run ROMs, if you can find them. As the consoles get newer, ROMs get harder and harder to find. For example, NES ROMs are everywhere, but Nintendo Gamecube ROMs are almost nonexistent.