[citation][nom]DaddyW123[/nom]I don't know if this trick still works, but it did on Vista... Just use your Windows 7 upgrade CD to install a fresh copy of windows (format HD) without entering the keycode and uncheck "auto-activate". Then install Windows 7 again over Windows 7 as an "Upgrade" this time with the keycode.[/citation]
I tried to install my "upgrade" Win 7 license on a new hard drive, after the old drive it was on burnt out. Windows 7 would not take the license and flagged it as a clean install. I contacted Microsoft, and after one hour on the phone with them, they refused to allow me to use the license, and one rep hung up on me. Horrible service. Save yourself the aggravation, don't use the upgrade license to do a clean install. Microsoft's license activation reps refused to help me get my old license to work on the new hard drive.