All computers have a fan installed inside to keep them running smoothly. When the computer overheats from excessive use or age, the fan runs faster to keep the temperature down. When there is minimal work being done on the computer and the temperature is cool, the fan tends not to run. If your computer is constantly overheating and the fan isn't running, you can change your fan's settings using the Control Panel.
Click on "Control Panel" in the "Start" menu. The Control Panel will open in a new window.
Click "Performance and Maintenance" in Windows XP and Vista and "System and Security" in Windows 7. Click "Power Options." The "Power Saver" window will open.
Click "System Cooling Policy" under "Processor Power Management" in Windows 7. In Windows XP and Vista, find "CPU Processing Speed." There will be a sliding bar next to it.
Slide the marker on the bar to the right to increase fan speed in Windows XP and Vista. Click "Active" in the drop-down menu under "System Cooling Policy" in Windows 7. Click "OK" to confirm the changes.