My brother got WinXP to run off of an install that took up about 300-400mb of harddrive space. Considering that it usually takes nearly a gig, I'd say that's pretty good. However, he apparently removed some essential software, since he couldn't install, or uninstall, anything, including additional hardware, or software... He got it running in a much more useable manner at about 500mb. Though, that machine got fried (I think the power supply went bad), so he lost that install. He hasn't bothered to cut down on WinXP's install since then, so he's not to sure what you can remove without it not working anymore. Though, I suppose with the way HDDs are these days, 300-500mb isn't as big of a deal anymore as it once was. Mouser X out.