Check the Key with Microsoft:
How to
contact MS support
For Activation problems, follow these steps and do a Phone Activation and hold on for a real person to assist you.
"How to Activate Windows 8 and 8.1 by Phone"
http://www.eightforums.com/tutorials/24636-activate-windows-8-phone.html
OPTION TWO
To Activate Windows 8.1 by Phone
1. Do step 2, 3, 4, 5, or 6 below for what you would like or able to do.
2. Press the Windows + R to open the Rusluisn dialog, type
slui.exe 4, press Enter, and go to step 7 below.
3. Open an elevated command prompt, type
slui.exe 4, press Enter, and go to step 7 below.
4. Open the Power Users Tasks menu, click/tap
on System, and go to step 5A below.
5. Open the Control Panel (icons view), and click/tap
on the System icon.
A) Click/tap on Activate Windows at the bottom right corner under
Windows activation, and go to step 7 below. (see screenshot below)
6. Open PC settings, click/tap on
Activate Windows on the left side.
Etc.
Cheers.