Perhaps check the BIOS, you may have a temperature alarm that is set low.

Menno Hershberger wrote:

> One of our phone company's computers has started beeping quite regularly
> for no particular reason. I went into sound properties to compare it and it
> is definitely the "default beep". When it happens, there is nothing
> blinking in the system trap, or anything else to indicate what might be
> triggering it. The event viewer reveals nothing. It is almost certain to do
> it when you open Outlook Express, but it doesn't jive with keyboard strokes
> or mouse movements. It's like 4 or five in a row, then some quiet, and then
> a couple more... just randomly. It also does it in other apps and was even
> doing it when I went into the control panel to compare the sounds. If you
> walk away and do absolutely *nothing* then it will stop.
>
> Is there a way to "trap" the source of these beeps?
>