I recently purchased the $40 windows 8 pro upgrade deal. I already had windows 7 and was in the process of upgrading my computer to 32gb ram and a ssd so decided to take advantage of the offer.

I got the Windows 8 pro install utility to generate a iso for me and then made a usb boot stick and proceeded to install windows 8 as a clean install so I could start from scratch.

The problem came when I tried to activate windows and it said I could not. Even though windows 8 allowed me to perform a clean install the activation said I could not activate because I used the windows 8 upgrade to do the clean install?

After some searching I came across this article and it allowed me to activate my windows 8 installation.

http://www.ghacks.net/2012/10/27/windows-8-upgrade-clean-install-possible/

• Open regedit by pressing Windows-q, entering regedit and selecting the result from the list of hits.
• Navigate to HKEY_LOCAL_MACHINE/Software/Microsoft/Windows/CurrentVersion/Setup/OOBE/
• Change MediaBootInstall from 1 to 0
• Go back to the start screen and enter cmd there.
• Right-click Command Prompt and select to run it as administrator.
• Type slmgr /rearm on the command line and hit enter.
• Reboot Windows now.
• Run the activation utility afterwards, enter your product key to activate Windows. (I didn’t have to do this step it was already activated)