Brief Intro to BIOS Overclocking
Using the computer BIOS is not only the most popular way, but also the best way to overclock CPU and RAM. A computer's BIOS is basically the software/firmware that allows your motherboard to work and be compatible with all of your PC's other components. Thus, the CPU and RAM memory. The BIOS is the foundation of your PC.
Accessing your computer's BIOS is done by pressing an F-Command key, or other key when you first boot up your computer. Likely, you will see the BIOS screen briefly appear before you see the Windows is loading screen. Upon entering the BIOS, you will be able to change many specific variables and motherboard settings, allowing you to overclock your CPU and RAM memory.
Not all motherboards officially support overclocking. For example, branded PCs such as Dell, Gateway, and HP often have limited BIOS options, with no option to adjust front side bus, and other CPU regulators. Commonly, branded PCs also restrict RAM overclocking, as there is no option for adjusting RAM speed.
Custom build PCs on the other hand, normally have very good overclocking options. This is actually one of the main reasons that people choose to build their own PCs.