Hello all. I have a Dell Dimension 8400 that seems to be about to give up the ghost. I have been told by various people that the problem is the motherboard, but I've also been told that replacing the old motherboard in a Dell is no small task. I would like to, if possible, replace everything except the Hard Drive, RAM and Video Card, if that's possible. I'm particularly keen on keeping the hard drive, since I've got all my stuff in there the way I like it AND because I have a perfectly valid WinXP install. Can someone give me some solid information on how doable something like this is?

Take a look at the post here from Hardware Central forums. This should provide you with the information that you need.