It's an OEM copy of XP, it's all newegg sold. They guy was real cool about it, he asked if I had ever installed it before and I said yes, I built the machine myself and had to format and reinstall and he said okay and gave me the new number. I tried to get free support from MS through their site and it took my numbers and said "you've got an OEM version, call your OEM manufacture" though so I'm screwed if I need to talk to them.