Bios setting problem

Question

please can you tell me how to repair my bootup windws xp.when i start up the computer it boots up to f8 and not straight to the desk top.when in f8 it asks which operating system to boot up to windows xp counts down 30 seconds then to the desk top like it should do how do i bypass the f8 and straight to the desk top please.thankyou.ken.