Checking if your Product is Activated
The easiest way of determining whether your Windows 8.1 is activated is by right clicking the start button (or pressing [Windows] and [x]) and then selecting system:
The Windows 8.1 Edition installed will be listed at the top.
The system properties screen will give you your activation status at the bottom. If your Windows 8.1 is activated as it should automatically be in most cases, you don't need to do anything else regarding product activation.
Online Product Activation
In this case the system is not activated. Select activate Windows and input your product key.
Select Activate Windows and input your product key.
If activation is successful you will then be told Thanks, you've finished. Press close and restart your computer.
If the key has been activated too many times you may be prompted for phone activation.
If your key is rejected and is correct you may need to input it via the command prompt.
You may verify the activation by closing the system properties Window and then launching it to look at it again.
If your computer is offline or the key has been activated too many times within a given time interval you may then be prompted for phone activation.
Once your product key has been input you may begin phone activation by pressing [Windows] and [r] to bring up the run command and type
Phone the number and input all the numbers of the installation ID into the phone as instructed.
You may verify the activation by looking at the system properties again