Chose Activate Windows by phone
The toll free number is: 1-888-571-2048
On Step 3: Click "Change product key"
Enter in your Windows OAM product key - on the Genuine Windows certificate hologram
Windows should give you a 54 digit Installation ID. (Step 3) broken into 9 sets of 6
Say or key in those numbers in the 1-888-571-2048 prompts
If it is valid, it will give you 7 sets of 6 digit numbers to go in each of the A B C D E F G boxes.
Once it activates successful, you will need to reboot the server