From the latest edition of Fred Langa’s Langa List (item 3) this tidbit of information …
Almost all PCs go through some kind of audible Power-On Self Test or “POST” process when you first turn them on. If nothing’s wrong, the PC usually emits one beep, meaning “All is well!” But if something’s not OK, the PC emits two or more beeps in a specific pattern. If you make note of the beep pattern, you can look it up in a suitable reference to see what the POST is trying to tell you.
For example, this page will fill you in on all of the standards error codes, while another version of much the same information may be found here.
And here, all along, you thought the beep you hear when your computer ‘boots up’ was only an annoyance.
