My BIOS doesn't have an option to set the warning or shutdown temperatures of the CPU. Is there an alternate way to do this, like a program?

It would help if you told us the make/model/speed of your CPU & what board you have. If you have a P4 or A64, you have nothing to worry about. Asus A7N8X-X 1800+ @ 8.5 x 200MHz 768MB PC3200 2.5-3-3-7 Asus A9550GE/TD 128MB WinME/WinXP Pro

I have a Intel Pentium 4 3.0 ghz, and an ABIT IS7-E motherboard. Why don't I have anything to worry about? My PC locks up if the temp gets do high and I want to raise the shutdown temperature.

If the temperatore guess beyond 65C you may want to invest for more cooling devices. Did you read the mannual from ABIT yet? http://www.abit-usa.com/products/mb/manual.php?categories=1&model=80 http://www.abit-usa.com/products/mb/products.php?categories=1&model=80

"Why don't I have anything to worry about?" What I meant was you don't have to worry about overheating. When the P4 gets too warm, the 1st thing it will do is throttle back...but if it continues to heat up & reaches the built-in "trigger" temp, it will shutdown on it's own. If you're system is locking up, the problem may not be heat related. I notice you didn't provide us with any temp readings? Asus A7N8X-X 1800+ @ 8.5 x 200MHz 768MB PC3200 2.5-3-3-7 Asus A9550GE/TD 128MB WinME/WinXP Pro

Oh sorry about not providing any temps. It's about 55-65C at idle, and I assume that it goes beyond that when I play games. As odd as it may sound, it was running fine at these hot temperatures for over a year without a hitch. My system will lock up a few minutes into gameplay and this high pitched beep will constantly come out of my speakers, like a warning tone or something.

That is your overheat warning and raising the warning theperature won't help you. You need to do some serious cleaning inside the case and invest in extra cooling fans. remove the heatsink and carefully clean off old thermal compound and apply fresh. You need to lower the temperature, not raise the warning threshold. I used to have a signature but it disappeared and I just couldn't be bothered writing another so please feel free to ingore this.