Windows 10: I got a activation key and activated on parallels. But the key is not reflecting in my acoount.

I have a doubt. Can two systems get activated using same windows key?

:)

 

oem activation key

If it is a UEFI Bios you shouldn't have to enter the key at all. If it is you will have to enter your key again and run activation. Even if you do swap boards the key will work.

 

oem activation key

You most likely wont even have to enter the activation key if you are only doing a reinstall on the same motherboard.

 

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.