My laptop's fan is making a loud sound similar to buzzing and even vibrates. Could someone tell me if I just have to clean the dust inside the laptop box or I have to take it to a specialist?
You can try to open the laptop by yourself, cleaning it and fix it if, by chance, some parts have somewhat loosened.
If you still have problems, you can buy a replacement part (I would suggest trying ebay) and substitute it, usually it's a very simple work. If you are unsure on how to do it properly, you can look in your laptop's manufacturer's website for your specific model "disassembling manual", "service manual", or the like. You can also try to search sites like http://www.ifixit.com/ or http://www.fixya.com/ for specific guide for your model.