A beepin beep is getting on my beeping nerves

Hello,
the problem is that when i turn my computer on, before it gets to the bit where you log on it makes a beep sound. it does it when its loeading before it gets to the bit where you log on...if that makes any sense.

i was just wondering if it was normal, why it beeps and could it be because of a virus??
b.t.w i have windows xp and a toshiba laptop. im nt sure what make or code or watever, i not that good when it comes to stuff like this.

hope sum1 can help me. thnx
:)