Well, I suspect an incorrect setting is the cause of the incorrect CPU speed you're gettting. So, yes, as previously stated, you need to access your CMOS Setup Utility, find the screen where you can change the CPU (perhaps memory, too) speed setting, change it, save the setting, and proceed to bootup.
One caveat: my BIOS actually gives me the option to choose a setting which would make my processor run faster than the standard 1.8GHz which is it's standard speed. I tried that once and my computer would not run at that setting.
Ideally, you would have a motherboard manual which would show the various screens in your CMOS Setup Utility. If you don't have that, you could probably download it from the manufacturer's website if you know what make and model motherboard you have. If you don't know, run Belarc and look at it's report.
