I'm actually in the process of converting a BSoD'd XP Machine into a server. I ordered a 40 Pin IDE to SATA M/F Adapter, and a 4 Pin IDE to SATA Power Adapter today to get my old files off of the computer (mainly Blockland :p), as well as install Windows Server 2012 and SQL Enterprise on it. I'm going to replace the Pentium inside of it for a Xenon, as well as maybe replace the RAM on it.
Will be bragging that I have $30,000 worth of software running on it ;)