Beep, Beep

This is a problem that a friend of mine is having with 97 mustang, and he dosen't have a computer. His dicription of the problem is this" when I first start my car I hear five beeps from it, it then makes this beeping sound 5 times in a row. Producing 25 beeps before it stops. Then about every 40 minutes while driveing the car it will beep 5 more times. He cannot find an explaination for this and he cannot seem to stop it. Can anyone tell me what it is so I can pass it on to him? Thank-you S.