When i first built my computer I put in Vista just so i can use the 64 bit OS with my 12 GB RAM. It didn't crash on me ever. Though it was heavy, I checked process and there was a SHIT ton of wasted memory being used by god knows what. Win 7 is much lighter and faster. Games and programs open up easier and run smoother. Its customizable and user friendly. XP > Vista, Win 7 > XP/Vista.