Windows 8: Enter Product Key

Problem
If you install Windows 8 and you can't activate it, possibly your product key is incorrect. In this case you need to enter a new product key. But how? At least on the Windows 8 Preview edition I installed in August 2012 it was not obvious.


Solution
After some searching on the web I found and tried this solution, it works!

1. On the Start screen right click on the background
2. Click All Apps (bottom right)
3. Right click on Command Prompt
4. Click Run as Administrator
5. At the C:\Windows\System32\> prompt type:  slui 3   [Enter]
6. Wait a moment and a window will prompt you to enter your Product Key.

Reference
http://www.windows7hacker.com/index.php/2012/08/how-to-change-windows-8-product-key-to-complete-activation/