Reactivate Win7 Student Upgrade

I bought the Student Upgrade for $30 last year to upgrade from XP to Win7. Since then, my hard drive has failed. I bought a new hard drive, and installed XP that came with the laptop.

How can I reinstall Win7? I have the Activation Key from the last time I bought it. I tried putting an ISO file on a DVD using this link Microsoft Fixes Windows 7 Student Edition Upgrade Problems

Windows 7 loaded up fine, but the Activation Key didn't work. Is there a way I can re-use my activation key from the first time I upgraded to Win7?

Keep in mind this is the Student Upgrade from Digital River (I believe it was Windows 7 Professional).

Thanks

If you used the download MS posted to make good on Digital River not supplying an ISO on Student Deal, it is Home Premium version.

If you have a Pro key, you need to run this tool on the ISO to unlock all versions: Ei.cfg Removal Utility Lets You Use Any Product Key With Your Windows 7 Disc

Then burn an all-versions DVD using Windows Image Burner or ImgBurn at 4x speed, boot it, choose your licensed version to clean reinstall using Custom>Drive options to repartition and format. Clean Install Windows 7

Here are tips to get a purrfect reinstall: re-install windows 7

Check your Windows 7 Student edition Upgrade email, this will tell you which Windows 7 you have.