The main reasons, which may hang the laptop are: overheating of the CPU, disconnecting the contacts of the chip or incorrect operation of the software.
To find out why the laptop hangs, first determine whether it overheats during operation, after a temperature measurement using the HWMonitor utility. Download it from the Internet, install and run. Then turn on your favorite program or game that loads the laptop. While you will work/ play with the program, HWMonitor will record maximum temperatures. Fifteen minutes later, exit the game and see what shows utility. The processor the temperature should be from 75-80 degrees. For graphics card and chipset up to 90, and for Winchester to 55 degrees, if the above means overheating.
If you think that the laptop freezes because of dust clogged in the cooling system, clean with the replacement thermal paste. If possible, contact the specialists of the service center, which for a small fee you all will clean. If this is not possible, try to clean themselves.
To do this, turn off the laptop and disconnect from the network. Flip it upside down and pull the battery. Then consider how to get to the fan. Often have to remove the cover, which is fixed on the bolts and latches. Once the cover is open, remove the fan, clean the blades and the radiator with a dry cloth, tissue or brush. Then proceed to replace the thermal paste, but keep in mind, this requires experience and knowledge. So if you do something wrong, the warranty is lost.
Believing that the cause of the unresponsiveness of the laptop is incorrect operation of the software will clear the memory from unnecessary programs and check your computer for viruses.