I had purchased a physical Windows 8 Pro DVD box set (Windows 8 box with 32 and 64 bit DVD's enclosed) from the local Staples Office supply in January 2013 so I could install it within a VM just to test stuff as needed. Anyway, at that time it cost about $55, but the box was a little mis-leading and in fact was a Windows 8 Pro upgrade. No big deal there as I have lots of prior Windows version I could use. However, I wanted to do a Clean Install of Windows 8 Pro.
It installed perfect with no warnings, etc. However, after doing the Windows updates it rolled all those back and then wanted me to activate Windows (which I thought it had already done this). It wouldn't allow this to happen as it stated it was an upgrade and no prior version was found.
Just in case anyone needs this info, the following link about making one change to a registry key, and one command in a CMD window fixed it with nothing else required. So, the upgrade did allow me to have a clean install for testing after the changes were made as mentioned in the link.
http://answers.microsoft.com/en-us/windows/forum/windows_8-windows_install/windows-8-pro-upgrade-product-key-cant-be-used-to/1726d238-98fb-4634-a468-04645a8ee097Here is all I had to do.
1. Run the registry editor (regedit)
2. Find the following key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup\OOBE
3. Change the value for 'MediaBootInstall' from 1 to 0
4. Open an elevated command prompt (run as admin)
5. Run the following command: slmgr -rearm
6. Reboot
