Can someone help me optimize my settings on my computer?

My friends dad built this computer for me a long time ago. It crashed so he had to do some weird stuff to it. basically something called the bios on the mother board I move when the computer wont start up using the power on. He also told me something to do to optimize the settings on my computer ,but i forgot how but I know its in the begging when you start it up like f1,f2 etc. someone know how to do it?