Windows 7 FTW! Really though, the ONLY reason you NEED to upgrade from Windows XP to Windows 7 is if XP cannot support your software. This will happen, considering it came out in '02. If you're running Vista now, upgrading to Windows 7 should be a no brainer. I couldn't tell you how many times I dealt with crashes in Vista and had to be much more cautious about memory usage because Vista was just plain bloated. Of course though, if you just like to see newer things, Windows 7 looks SLIGHTLY better looking than Windows Vista on the outside. There's a MUCH more visable change between Windows XP and Windows Vista (or even Windows 7). The XPM feature is pretty sweet, too, although I don't have much use for it. I'm on Windows 7 Ultimate OEM 64-bit.