Like Darth Android said, check the BIOS. There might be fan speed settings. I would also recommend installing a program to check the CPU temperature or you might be able to check the CPU temp in the BIOS. Sometimes temperature gauges break and report outlandish numbers. If this is the case, you can try to manually set the fan speed using "speedFan". You'd have to make the program start up with windows for the changes to stay on reboot. This program can also tell you the temperature readings for most hardware.
http://www.almico.com/sfdownload.php
Edit: Also make sure the heatsink is on tight... the CPU might actually be overheating.