Computers always accumulate lots of dust near the fans. On desktop laptops it can be seen more easily but on laptops it is always in the inside of the heat sink, so it can not be seen unless you?disassemble??it. If the dust is not cleaned regularly a thick layer will form and the airflow will be interrupted. As a result the temperature of the pc will increase and performance will be lower. If the temperature increases too much, the computer will freeze or reboot. Also some components such as the hard disk or the CPU may break.