You just discovered a dirty little Intel trick. They locked the multiplier on their CPUs several years ago. Therefore - you cannot change the multiplier. In your case it's locked at 4.5, forever.
But you can still overclock the chip.
Multiplier X Frontside Bus Speed = CPU core speed
Your processor is meant to run like this:
4.5 X 100MHz = 450MHz
Since you can't change the '4.5' to anything higher or lower - you must raise the Frontside Bus Speed(FSB) to something higher than 100MHz in order to overclock the chip.
You might have a 112MHz FSB setting on your motherboard. That would do this:
4.5 X 112MHz = 504MHz
The downside to changing the FSB speed is that the PCI and AGP(graphics) port bus speeds will be increased as well.
The PCI bus speed is a fraction(1/3) of FSB speed. Also the AGP port speed is a fraction(2/3) of FSB.
While most hardware can tolerate the elevated bus speeds - some can't. The data on hard drives can be corrupted if the FSB speed is raised because the IDE controller is using the PCI bus(which is running fast because the FSB has been raised).
The FSB speed is also the speed that your RAM is operating at. So, expect memory-related errors as you approach the limit of the RAM. You can purchase memory rated for faster speeds than the PC100 you most likely have now. PC100 means the memory is good for 100MHz FSB or slower. The next available speed is PC133, good for 133MHz FSB. Your PC100 is probably good for 115MHz, sometimes more, sometimes less.
OK, I'll stop here.
Ask some more questions
P4 email@example.com dual R134A phase change chillers with 600watt thermoelectric array. Capable of -70F
Nixie tube numeric display control panel and pneumatic motherboard tray.