Installing Windows XP on a homebuilt PC with a used copy of XP

To be honest I'm not 100% sure if it is legal, but you should be able to use the code for XP from the PC that died. Mainly due to the fact that that computer is not in use anymore, meaning that that specific install of XP is not in use either. If you are really concerned with the legal aspect of it, just transfer the HD to the other computer if that isn't a part of the PC that died.

Yeah, I was thinking about doing that. The hard drive didn't die, but I could have sworn there was something that bound the installation to the cpu/mobo of the old one. Is it possible to call up microsoft and get a new product key, because I was searching around and saw some stuff about that.

With a full retail version you should be fine to install it on the new system. The licensing agreement allows the installation of 1 key per 1 machine. I had a system that I replaced years ago and called Microsoft about this. The only thing they wanted to know was if I had removed XP from my old machine. The person I spoke with stated that as long as I only had it installed on 1 machine at a time I was not violating the licensing agreement.

Alright, thanks a lot.