[SOLVED] How do I get to my BIOS?

Ok for some reason when my computer starts up it doesn't show the dell loading screen where i can press F2 to get to the setup. I've read that if your using a USB keyboard that this might happen. I do not have a PS/2 keyboard and was wondering if there was any other way to get to the bios screen. Also the reason why i'm trying to get to the BIOS screen is so i can change my start up to read my cd/dvd drive and not my hard drive so i can reformat. If you know a way to do this without going to the bios plz post