How to Change/Install Windows licence key using CMD - Command Prompt.

Installing licence key and activating windows using command prompt.

1. On Start and type CMD and run it as Administrator

2. Type slmgr.vbs /ipk XXXXX-XXXXX-XXXXX-XXXXX-XXXXX and press Enter.

3. Then type slmgr.vbs /ato and press Enter to activate the licence key.