"Microsoft Office (any app) has not been installed for the current user"

"Is it possible that the OEM Key and Volume License Keys for that have both been revoked by Microsoft?

Depending on where you bought them and through what Channel, they still may be pirated, and Microsoft may have finally gotten around to locking them down. You should call Microsoft's Support line for better help diagnosing the issue.

You may wish to look at www.microsoft***/howtotell/default.aspx?displaylang=en"