820 to LPAY 870 an error says the OS keys are invalid

820 to LPAY 870 an error says the OS keys are invalid

The operating system keys may not be active and therefore you will need to try activating them again. Run the computer as the administrator and then go to its system properties and try activating the keys from there.

If the activation refuses to work in the normal mode, you will need to run the computer in safe mode and then try activating the operating system from there. Be sure to start the computer after you have done the activation for changes to be effective. You can do the activation on the internet or use the CD that you used for installation of the operating system. In case that does not work, then you might need to reinstall the operating system.

-Mathew Stone