Where to find the Windows 10 license key on the surface book?

Where can one find the key of the installed windows 10 operating system on the surface book?

I tried to find it on the case and asked google but couldn't find an answer.

Solution 1:

According to Microsoft:

How to find your product key depends on how you bought your copy of Windows 10:

• If you bought Windows 10 from an authorized retailer, the product key will be on a label inside the box it came in.
• If you bought a digital copy of Windows 10 from a Microsoft website, the product key will be in the confirmation email you received after buying it or will be distributed digitally as an entitlement, in which case you won't receive a product key. For example, if you upgraded to Windows 10 for free, you'll receive an entitlement instead of a product key.
• If you bought a new PC running Windows 10, the product key will be pre–installed on your PC and your PC will automatically be activated, included with the packaging the PC came in, or included on the Certificate of Authenticity (COA) attached to the PC.

I would assume it is in the box the Surface Book came in.

Solution 2:

You can get the product key using:

wmic path softwarelicensingservice get OA3xOriginalProductKey 

Note: Please run the command with admin privileges ii won't work directly