I received a "Windows must be reinstalled to activate" message.
If Windows is not automatically activated, you can resolve the issue without rebooting.
An the command prompt do the following:
Type: net stop slsvc (It may ask you if you are sure, select yes) Type: cd %windir%\ServiceProfiles\NetworkService\AppData\Roaming\Microsoft\SoftwareLicensing Type: rename tokens.dat tokens.bar Type: cd %windir%\system32 Type: net start slsvc Type: cscript slmgr.vbs -rilc (It may take a long time for this to complete, please be patient)
The license should now be able to be reactivated without full reinstallation.