To be fair, he did not ask for help bypassing activation, but help for an erroneous report that his software is not genuine. We all know that software can be buggy and there is no magic rule that Microsoft's validation methods are always correct. Also there's no guarantee that someone else hasn't stolen the key. There are a million ways this could happen.
So on the basis of the principle that we're "innocent until proven guilty", I'm going to assume that you do indeed own a legitimate licence. I myself have had Windows report that it "is not genuine". It happened to my legitimately-owned and licensed copy of Windows 7 64 bit Ultimate. A few days later the message mysteriously disappeared with no action on my part. It was a mistake. They happen. See if this works for you.
If that fails, I think your only recourse is to Microsoft customer service. Explain very clearly what happened and be ready to prove that you are the legitimate licensee. Hopefully they will be able to help. I must add the warning however, that if you did obtain the copy fraudulently or if you have multiple installations, you are committing a criminal act and are liable for prosecution.