We can’t vouch for this hack, because we are too lazy to try it (and we never, ever violate copyrights or EULAs), but kind reader Martin explains the process for turning an Windows XP Home install disc to a Windows XP Pro disc after the jump. It sounds pretty simple to do (just some registry changes), but you can’t install Service Pack 2, so you might try to slipstream in the changes to your modified install disc (if that’s even possible). Alternately, buy XP Pro, or get a Mac. Code: yes indeed, you can’t change an installed Windows but only your Installation CD (or even a recovery CD in case the manufacturer had not left out important parts) Here’s the detailed breakdown you asked for. 1. Copy the root directory and the i386 directory of the WindowsXP CD to your harddisk 2. Extract the Bootsector of your WindowsXP CD 3. Change 2 Bytes in i386\Setupreg.hiv : a) Open Regedit b) Highlight HKEY_LOCAL_MACHINE c) Menu: File -> Load Structure -> i386...