An Inspiron 1720 laptop is made by Dell. Laptops contain fans that which cool the central processing unit. If the fan gets excessively dusty, it may not be able to function properly, which can cause the computer to overheat and shut down. A laptop fan should be cleaned as needed to remove dust. A laptop should be wiped down regularly with a dry or slightly damp cloth to remove dust and prevent it from entering the fan. Be sure to read the instruction manual for cleaning a fan and follow all directions carefully. Improperly cleaning the fan could void the manufacturer's warranty.
Unplug the laptop. Remove the battery by pushing the button to unlock the battery.
Unscrew the screws holding the plate at the bottom of the laptop in place. Remove the plate. Under the plate is the fan.
Using a slightly damp cloth, wipe off any dust on the removed plate. Allow the plate to air dry.
Spray the fan with compressed air to remove all of the dust. Using a cotton swab, hold the fan blades in place so the air doesn't blow the fan in circles.
Place the plate back onto the bottom of the laptop and secure it.