Windows 10: Windows activation key used up doing failed installation, how to recover it?

I tried to install Windows 10, but doing my first to tries it, instead of rebooting in to windows and finishing the install, it booted into Linux Mint on an secondary drive, which wasn't my first boot priority. Only after disconnecting the secondary drive did Windows install. Doing the first try i put in my Windows activation key doing the install, and now when have it says it is already in use. How do i reclaim it, as it isn't being used?

:)

 

Installing Windows 10 using Windows 7 key

Nope, you need to install Windows 10 first and make sure the Windows 7 key is transferred to your Windows account after you've installed Windows 10 (not quite sure how that works). I missed the last step and I could not activate Windows 10 after a re-install... Microsoft seem to have done everything they can to make it a PITA. Also, it's technically too late to do this now anyhow, as the upgrade offer has expired. But KMSPico works quite well...

As for getting rid of Windows, delete the Windows folder.

 

activate windows 7 oem key

There is no difference between the OEM disc and the Retail disc with Windows 7. A retail disc will accept a OEM or Retail key, and vise versa.

If the OEM Key wasn't going to work with the disc you have, it would have stopped you during the install when it first asked you for the key, not during activation.

What is likely the problem is that, since the OEM version has already been activated once, it is failing activation again. Activate it over the phone using the option given to you on the failed activation screen, and you shouldn't have a problem activating it.

 

Installing Windows 10 using Windows 7 key

Two quick ways to use your Windows 7 key during the install:

1. When asked for the serial #, put in that Windows 7 serial # and continue on. It should activate as soon as it hits an internet connection.

2. When asked for the serial #, at bottom of window click on the I don't have a serial # text (or whatever it says). It will then ask what version you want to install, ie. Home or Pro. Be sure to install the right version that matches your Windows 7 key. Then once you get into windows you can activate by putting in the key. Some people prefer this method, not sure why honestly. Easier to do #1, since the installer will see your key and know which flavor of Windows 10 you are trying to install.