How can a legal entity confirm the legality of a free upgrade to Windows 10 in case of verification?

Question

Windows

For example, a check came in: according to the license documents Windows 7, and Windows 10 is installed. What document can be used to confirm the legality of such a transition?
I hope it won't be necessary, but it's better to play it safe, given the stories about the fact that licenses are sometimes checked for Linux as well.
I was looking for an answer specifically for legal entities without a Software Assurance subscription, but I did not find it. The only thing that was advised on the hotline was to write a request to the Microsoft info center and wait for an official response, which will be a confirmation.

Answer 1

If your software was purchased through corporate distribution channels, then everything depends on the subscription. A one-time purchase of Windows 7 GGK licenses does not entitle you to a free upgrade to Windows 10, as commercial use of Windows 10 is covered by a separate license agreement. If you have a subscription with the right to receive new versions of the OS and software, then you update under this agreement, which should not cause questions from the supervisory authorities.

Answer 2

When checking, they require purchase confirmation documents + IMHO, in your case, a printed document with a link to the original (descriptions of the update rules on Microsoft) that the company allows you to upgrade from license A to B (similar to Linux)