The fan in a laptop is a crucial component and if it is working all the time and not pausing then you need to act sooner rather than later.  Basically the fan is used to remove excess heat from the laptops main board, primarily the CPU (computers processor).

On some occasions just switching off and on the laptop will stop the fan from running all the time.  However, if this does not do the trick, then the fan is probably blocked from the inside.  This is a extremely common fault for laptops, and some laptops are easier to clean than others.

The fan exhaust is usually on the top edge or underneath the laptop, the area is usually very hot to the touch if the laptop has been on and if the fan is running you will easily spot its location because of the noise it makes and the heat in that area.

Once you have identified the fan, have a look at the back of the laptop casing.  See if the back plate can be removed for the fan section ONLY.  If this is the case, the fix will be quick and painless, if not then I would suggest taking the laptop to an engineer to dismantle the laptop assembly.

Before removing any screws on a laptop, ensure that your warranty will not be voided if you proceed, Also note that Clickhappy or any of its technicians are not liable for any damage or corruption caused by attempting this repair.  information contained within these Self Help files are for use by public at their own discretion.

OK, we are now going to remove the backing plate for the fan, there will be a few small screws on that backing plate.  They should all be the same size remove them and if you look around the edge of the backing plate there will be an small spacer to use to prise off the plate.  The plate is usually held in with clips which pop off when you lift the plate.

You need to earth your self before opening a laptop case as laptops and PCs are very susceptible to static electricity.

Now that the plate has been removed, you will see the fan with 3 screws holding it into the motherboard.  Unscrew these screws and remove them from the fan.  Now carefully lift the fan from the case being careful not to pull the small power cable attached to the motherboard.  remove any accumulated fluff or dirt from the front of the fan, use a small cotton bud and remove any dust buildup on the metal fins where the fan connects to the laptop case.. do not put the cotton bud onto the laptop motherboard.

Once all the dust/fluff and debris is removed from the fan, place the fan back into its housing and put the 3 fan screws back and tighten. (do not over-tighten them)
Next replace the backing plate and replace the backing plate screws and tighten them as well.  Power on the laptop and  check to see if it has quietened down.