Activation is a protection mechanism implemented in Windows 10 and earlier versions against piracy. It first appeared in Windows XP and exists with different changes and improvements in Windows Vista, Windows 7, Windows 8 and Windows 10. When activation is successful, usually it indicates that your copy of Windows is genuine. There may be times when you need to deactivate your copy of Windows 10 in order to transfer your license to another PC. Here is how you can deactivate your copy of Windows 10.
If you need to change the product key of the installed OS, for example. suppose you have installed Windows 10 initially with a generic key, and then wish to change it to an authentic key that you purchased, this can be done quickly without reinstalling. You don't need any third party tools or complex Registry tweaks. Note: This trick also works in Windows 8.1, Windows 8, Windows 7 and Windows Vista. Follow the steps below.