When i tried to update from windows 8.1 single language to windows 8.1 professional, the add new feature application in my windows came up with an error saying, process could not be completed, contact support.

I already have my key, but now I cannot use the key because I entered it to that add new feature application.

Please help

I have the same problem too. I already have keys from my universities. I want to upgrade my Asus S550CB Windows 8.1 Single Language to Windows 8.1 Enterprise Edition. When I enter the key to 'Get more features with a new edition of Windows' it says 'This key won't work . Check it and try again....'

I'm sure I have legal and genuine keys for Windows 8.1 Enterprise edition (even for Professional edition).

How to solve this problem?

Thanks.

luckily when I restarted the computer that day, it automatically did install the features and did upgrade to windows pro edition.
Even though it said, a problem encountered and this key wont work AGAIN, it did install the features once I restarted.
try restarting if you havent done it yet.
hope this works.

Thanks