Warning! CPU has been changed

[tabdlb]

When I tried to turn on my computer I saw this: Warning! CPU has been changed. Please re-enter CPU settings in the CMOS setup & remember to save before quit! It then acts as though it is going to open but then tries to restart. Then a warning windows did not finish loading on the previous attempt came up. It goes to start in Safe Mode. I see this warning: The problem could be caused by your network or hardware settings. Make sure these settings are correct in control panel & then try starting windows again. For more info see troubleshooting section in help. It will start in safe mode. I use Norton 2005 Antivirus. I ran that & it said no threats were found. If I try to start in normal mode I get the message: windows protection error. You need to restart your computer & the screen is black. I put in a new CMOS battery hoping to fix the problem. But no change. I tried running System File Checker while in Safe Mode. It came up with File corrupted - setupx.dll. I chose to restore the file. When I ran System File Checker again it didn't come up with anything. A little history of what I have: Windows 98 second edition; Main Processor: Intel Pentium 4 1.50 GHz; Main brd: Gigabyte GA-81RX; the computer was built so no name brand. Please direct me in what I can try next to get my computer to start up. Thanks!