I am unable to upgrade from windows 8.1 to windows 8.1 pro using pro pack with media center.
when i enter the key i get a message "This key won't work, Check it and try again, or try a different key".
To enter the key, I went to System, and clicked on "Get more features with a new edition of Windows" link, and selected "I already have a product key"
I have tried entering the key several times but i see the same message.
Best Answer
after spending sometime on the Microsoft support websites i found the solution . we just need to reboot the system.
This is a windows 8.1 upgrade bug because the system message is wrong and the it does not prompt for a restart.