Updated PC and need to re-activate. However I upgraded from windows 7 and lost the product key.

[Goblaz]

I recently updated my computer in all ways but the hard drive. This caused windows to not recognize the hardware and wants me to reactivate my OS. This OS was originally windows 7 and I used the free upgrade. However since I recently moved I lost the original windows 7 product key.

How can I activate my OS?

 

[Grizzly]

If you have used the free upgrade and have not made any major changes, your pc is supposed to be already secured with a hardware token on the microsoft servers. If you just installed your OS skip the key input at the beginning of the installation and let it finish installing. once you are online, your pc is suppose to be activated ( with a digital license ) automatically...

 

[Trouble]

I recently updated my computer in all ways but the hard drive. This caused windows to not recognize the hardware and wants me to reactivate my OS

If you've exceed the maximum hardware changes that Microsoft allows, then you are likely going to have to make the call and throw yourself on their mercy and see if they will help you.
Basically it looks to the OS like you are trying to use it on a new computer.

 

[Grizzly]

Darn, I read only the last part. Having exchanged everything but the hard drive is a major change of course. As Trouble said, call MS and be at their mercy. Maybe you get lucky.

 

[BigFeet]

If it's upgraded from a retail version, there shouldn't be any issue in getting them to reactivate it. I moved a Windows 8 upgrade from one computer to another and they reactivated it no issue.

 

[davehc]

There is an alternative, which can work, if you signed in originally with an MS account.
G to Settings - Update & Security - Activation. Click the “Troubleshoot” option if activation failed. Sign in with the Microsoft account with which you associated your license. You’ll have the option to tell Windows that you “changed hardware on this device recently”,, and select your PC from the list of devices associated with your Microsoft account.

Here is the original MS blog on the procedure

https://support.microsoft.com/en-us/help/20530/windows-10-reactivating-after-hardware-change


THis does not change the warning given by Trouble, regarding too many hardware changes.