How to: Activate a clean Win 8 install using an upgrade licence key

[evilsatan]

I thought this would come in handy for others as it just saved me getting angry.

The situation:

You currently own a licence key for another Windows OS which allows you to buy an upgrade key for Windows 8. You want a fresh install of Windows 8 as it will perform better than an upgrade and ensure your machine is clean but when you try to activate it will say "This key didn't work. Please check it and try again or try a different key".


The solution:

*Updated step 22.3.2013* - Microsoft are now blocking the modification of the reg key so follow the first step! If you are using an updated version of the installer this trick may not work at all!

Do not connect your PC/laptop to the internet during install. If you are on a laptop/PC then disable wireless and don't connect an ethernet, if installing to a VM don't add a network adapter until the last steps.

Start your new clean install of Windows 8

Launch the registry editor (Windows key + R, then type regedit and hit enter)

Go to this folder: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup\OOBE

Right click the MediaBootInstall key and click Modify

Change the value from 1 to a 0

Close the registry editor

Launch command prompt in administrator mode (Windows key + X, then click command prompt Admin)

Type 'slmgr -rearm' and hit enter

Reboot, enable network adapter and try to activate again, in most cases it will activate automatically


Hope this helps some others