My 2 year-old Dell recently suffered a motherboard failure. Naturally, the MB is no longer available... And, the MB was proprietary for that specific case (cabinet).
So, I bought a new ASUS MB, 3.0 gig P4 and a new case. I moved over everything else. Then, I found my older version of XP was crashing on start-up. Rather than install the latest version on the old drive, I simply bought a 40 gig Seagrave hard drive, loaded the latest and greatest version of XP and slaved the original to it. Everything on the original drive runs fine, plus I now have 120 gigs of drive space. I had to reinstall some drivers, and a program or two, but it was generally fast and painless (and I'm no computer geek by any stretch). Added another fan too.
Everything came to just over $400 and this baby simply flies. (See specs below).
My regards,
Widewing