System hung for an improper CPU Speed setting

I get this message, after I tried an older game in my system, which has a CPU speed of 2266:
During the last boot-up, your system hung for an improper CPU Speed setting. Your system is now working in safe mode. To optimize system performance & reliability, make sure the CPU Speed conforms to the specifications of your CPU."
After I get this message, which is found in my BIOS setup, and I exit, my system will not do anything. It goes to a black screen, when I exit.
Help!