For starters carefully examine the capabilities of your CPU. Better to do it by reading the description and on the site of the manufacturer. The fact that not all processors are amenable to overclocking, and among those with whom you can carry out this operation, a large part accelerated by 10-15%. This is clearly not enough to see the acceleration in the system.
Download and install ClockGen. This utility is especially created to modify the settings of the CPU in the Windows operating system environment. With this program you can increase the clock frequency of the processorwithout having to configure the BIOS.
If you increase the frequency of the processor is not enough, you have to resort to the setup in the BIOS. When you start the computer press Del. Once you get in the BIOS press Ctrl+F1. Depending on the manufacturer of the motherboard, configure CPU in BIOS can be in different sub-menus. Usually, this items: CPU, Advanced or Advanced Chipset Features. The overall frequency of the processor is obtained by multiplying the index multiplier to index the standard frequency. These settings should increase gradually, rebooting the PC after each change. Periodically increase the voltage supplied to the CPU, because the work at a higher frequency requires more voltage.
Make sure the cooler and the integrity of thermal paste.