Recover a lost product key from a Microsoft Surface

So, if like me you find yourself rebuilding your MS Surface but also forget to take note of the Windows product key, the good news MS bakes it into the BIOS. After a bit of digging in WMI it seems its easily accessible, the easiest way is to run the following from the command prompt:

wmic path softwarelicensingservice get OA3xOriginalProductKey

Then just paste the result into the activation window.