Just a quick post for anyone that has a slow, noisy or overheating laptop. I did this method a few days ago and I have to say i'm impressed! ---FIRST TAKE THE BATTERY OUT--- So all you need to do is look at the bottom of your laptop for your CPU intake and out take fan, this is usually circular and you can see fan blades inside (http://www.mikescomputerinfo.com/images/laptop1.jpg). The next thing you need to do is to grab a vacuum cleaner and put a circular attachment on the end - I wouldn't suggest brush attachments because of static electricity. Turn on the vacuum and suck all the dust from the intake and the out take of your CPU fan, spend a good five minutes on it. You might start to see large clumps of dust peeping through the vent so to help dislodge these use some rubber gloves, they grip onto the dust and move it around getting it out of the vent. Once finished I also suggest using a flat head screw driver or a thin object to move the dirt out of the keyboard - some laptops have removable keys, if you are not sure about this, don't take the risk - then vacuum up this dirt. I also got a damp cloth and some kitchen roll - or tissue, to clean my screen and the rest of my laptop.
yeah i was scared at first too, but if you do do it make sure its been turned off for at least an hour, the battery's out and just be carefull and take your time, there is no rush