Command line Option
Product key: xxxxx-xxxxx-xxxxx-xxxxx-xxxxx
Run cmd as administrator and type in "almgr -ipk xxxxx-xxxxx-xxxxx-xxxxx-xxxxx" without quotes.
Press Enter , then type " almgr -ato " without quotes.
Again Press Enter and you are done.
Open RUN box and type “slui.exe 3”, hit enter
This command will open windows activation dialogue box, enter your product(activation) key and click activate.