Many of the motherboard currently shipping auto-detect the parts used in your system assembly and do not require the adjustment of the BIOS to work properly. If you feel the need or actually have to adjust the BIOS you need to hit the DEL or F1 or F2 depending on your system and this will take you into the initial BIOS screen. In the example below I show the opening screens for the two most commonly used BIOS. Once again this is where you need to read your manual to understand the performance features that can be achieved by a few quick changes. Be aware a wrong setting can hinder system performance greatly so be careful when making changes.