I recently upgraded my PC from Win 7 Home Premium to Win 7 Professional, but now every few days my desktop wallpaper disappears and turns solid black, and in the lower right corner I get the message that "This copy of WIndows is Not Genuine" and it then prompts me to re-enter my serial number and re-activate my copy of Windows 7 on-line. Has anyone ever encountered this problem before? Right before this happens I get a cryptic error message to the effect that there has been some change that has called the authenticity of Windows into question. It's pretty annoying to have to keep activating my copy if Windows 7 evety few days. Does anyone have a clus as to why this is occurring and how I might be able to resolve it?
Thanks for any and all advice!