Most BIOS's will have something come up on the screen to tell you how to get into the setup program. Usually it's either the (del), (f1), (f2), or (f10) keys. Sometimes it's (ctrl)(alt)(s) or (ctrl)(alt)(esc). I'd have to say the most popular is the (del) key. Once you get into the setup you'll just need to look around the menus for the boot sequence. You'll want it to say CD first. There's usually instructions on screen on how to change the settings. Then you need to save the settings and again there should be on screen instructions. There's at least 1,000,000 different bios's and versions of them that there's no quick and dirty answer of what you need to do. Pay attention to what the screen says and you should be ok.