The other method for cooling processors consists of taking advantage of a series of energy saving commands found in all processors since the age of the Pentium; using these orders, you allow the parts of the processor that are not working at that moment to ‘take a rest’, thus considerably lowering the temperature of the processor. This type of instruction is included as standard in the NT family of operating systems, whereas otherwise you have to turn to complementary applications such as Rain for Windows 9x or DosIdle for MS-DOS. Unfortunately, the system has an unsolvable limitation: when the processor is used to the maximum of its power at all times, cooling cannot be carried out; it is therefore hardly of use if, for example, you are playing a highly complex 3D game. Nevertheless, these programs take advantage of dead times of much less than tenths of a second, so they can always come in useful at least as a back-up for a good fan.
These programs are available on the utilities page.