Windows 7 Ultimate suddenly not genuine after 8months of use.

Hello. I recently received the "Windows 7 Build 7601" message. Like others, my screen is black with the exception of the shortcut icons. But, I can still access programs. The PC was custom built last February and was validated by windows when build was completed. This problem only surfaced after I replaced a faulty motherboard. Diagnostic report included: Diagnostic Report (1.9.0027.0):...