Look in your mobo manual- it might be a warning beep for undervoltage or something like that. I had a heck of a surprise one day when I heard what sounded like a loud police siren! It took a few minutes to realize it was coming from my case (It started simultanously with me clicking a web link, and I couldn't figure out why the web page had such an annoying wav all the sudden). Turns out one of my fans had failed, it was a hot day, and the CPU temp of 56.5°C had tripped the 56°C warning siren. Rather than replacing the fan, I fixed this by changing the warning to 60, hehe.
FYI, it was an SY-6BA mobo. (original, not + or anything) boy did I luck out with that unknown board- what a winner of a mobo!
[This message has been edited by grover (edited 08-27-2000).]
Pentium IV 2.4C Northwood- M0 stepping @ 3.2GHz HT
Air Cooled w/ SP-94 heatpipe & 92mm Vantex Tornado at 45C
4x256=1gb dual-channel 2-3-3-6 OCZ PC800DRAM @ 890MHz 3-4-4-8
MSI Neo2-PLS w/I865PE & SATA @ 4x267=1068MHz
BFG GeForceFX 5900@485/967MHz = 6284 3DMark2003s; dual-head 21" CRT & 19" LCD