The only real reason to upgrade to windows 7 is for directx 10 and above. Other than that, Windows XP is a perfectly fine operating system. If games are not a problem, or you don't care about directx, its a no-brainer. It will always be faster and use less memory, though it isnt because windows 7 is bloated. Primarily they have a different memory management system. I'll stop talking there and save you from the boring details.