If Evil's option doesn't work, you can change MBs, but when you activate it you'll be given a number and phone microsoft and just tell them your motherboard died (or whatever) so you're putting in a different one. I was using an OEM disc and switched from an ASUS to a GB MB and reinstalled and they helped me out. Maybe I just had a good customer service rep from MS though.
__________________ My System - Mimir
|- Intel i7 920 -| - Corsair 850w HX Modular PSU -|- Gigabyte G1. Sniper -|- 24GB Corsair Vengeance DDR3 -|- Prolimatech Megashadow Cooler -|
- EVGA GTX 670 FTW -|-2x Crucial M4 256GB RAID 0-|- Seagate Barracuda 3TB -|- WD Caviar Green 2TB HDD -|- Corsair 600T White -|- Windows 7 Ultimate -| |