Got four desktoppers in use here... three Vista/XP dual boots (one belongs to ma), and one XP rig that I just finished rebuilding from old parts leftover from upgrades. Yeah, I finally pulled my finger out and decided to face the beast after it decided it wouldn't boot up the first time around, upon which, I decided to hide it in the closet.
That was around nine months ago, give or take!! Oh if only I had been inclined/in the mood to investigate it back then... turned out to be just the IDE ribbon needed to be reseated properly. (Now where's that kicking myself in the pants smiley some us would find useful here?

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I also have another build in the works - has an old 476 socket P4 2.8ghz on an Asrock mobo with 2gb of RAM, a 40gb Maxtor HDD, a nVidia 7600GT GPU, a basic Soundblaster card and 17" BENQ CRT monitor - for my daughter and partner. I'm just waiting on them to come over with the OS and a bigger HDD to finish it. Their rig went guts up and they can't afford to get another one, so I figured they may as well have use of my spare parts as have them taking up closet space.