Why can't I activate Windows 10 Pro?

[Windows Central Question]

Can't activate windows 10 pro

This is happening after an upgrade from win 7/pro while online, followed by motherboard crash and replacement.

 

[arjan wolthuis]

Re: Can't activate windows 10 pro

If it does give an error code, try again, if You don't have your license key, you need to go back to w7 activate with w7 key and update again

 

[gpobernardo]

Re: Can't activate windows 10 pro

If you upgraded from Windows 7 Professional to Windows 10 Pro and then your motherboard "crashed" (usually, hard drives crash, not boards) and was replaced - presuming that the hard drive is still intact or was simply cloned leaving you currently with Windows 10 Pro, then you could rollback to Windows 7 Pro, enter your valid license key for Windows 7 to activate it, and then upgrade back to Windows 10.