Windows 10

But you should still care about the WD Community User Guidelines and Terms of Service while posting in the WD Community.

Keep it legal.

- You remain solely responsible to comply with applicable law in using the site. Accordingly, you should not post any material that would infringe on any intellectual property rights of any party including, without limitation, patent, trademark, trade secret or copyright.

On the other hand, did your computer come pre-loaded with Windows? If so, then it’s an OEM copy and the reason why Microsoft is recommending for you to contact your computer’s manufacturer since your computer’s Windows license was sold to them as a company, not to you as an end-user.