I messed up and lost my Windows key with my HTPC.

It's an Acer R3700. Basically over the weekend I replaced and upgraded the existing HDD and then re-formatted the original HDD to use as external storage in a caddy.

As I was installing Win 7 on the new HDD I first checked the case and then the box and found no Win 7 COA sticker. Uh-oh..

After some googling apparently the windows 7 key was attached directly to the original OS or may have been kept in restore partition which I just wiped. Bugger.