I am uncertain if you can use a retail CD, they might use a different algorithm for the validation. However, I do know from experience that I have used an OEM standalone XP CD that I sell to install XP cleanly on a couple of machines from folks like Dell, etc. If you have an OEM CD that would probably work, I hate the restore CDs anyway as they install all the garbage on the machine besides windows. I like to start with a clean windows only install when I redo a machine, not Dell this and Dell that software too. Good luck.