This is one of the new virus/trojan/malware problems. These can damage the OS to the point you see this message.
While the machine came with the OS, let's hope you have or created the all important restore media as repair is uncertain.
That is, if you look around you find folk reinstalling.
I did a virus cleanup and several things were deleted when the clean-up was done, and now there is "Windows Vista (TM) Build 6002 This copy of Windows is not genuine" down at the lower right corner. Vista was on the damn computer when I bought it and I haven't changed anything. What gives??
Gateway Computer GT5668E
AMD Athlon 64 x2 Dual Core Processor
3.00 GB RAM