If you know your way through Windows, go with XP. Friend of mine had Vista preinstalled on his laptop, and he'll be reformatting soon to put XP. He liked Vista for a while, but whenever he wanted to install a program or a game, tons of googling, patching, tweaking was necessary to get it running; and more than once he couldn't even get it to run either. The worse is if you like playing slightly old games... forget it. Some people say Vista eat up all your RAM blahblahblah... yes it uses far more memory, but it handles it much more efficiently too. Basically, unused RAM is wasted RAM, right? Don't buy that pro-XP argument.