I looked at the E310 manual and didn't see anything about disabling the "beeper".  The "beeper" is there as it provides diagnostic information (beeps) if there is a problem. 

 

I don't see any option in the BIOS to turn it off either, so I don't know what you "turned off".

 

I wonder if it's the dial-up modem that is beeping instead of the diagnostic beeper?

I turned off the onboard sound in BIOS.  I'm connected to a cable modem, so it can't be the dial-up modem that's making the noise.  The sound is definitely coming from the PC.  It beeps everytime I do something in one of my apps, but it'll also beep other times.  For example, if I go into sounds and audio devides, hardware tab, then click on properties for audio codecs, it brings up another window with those properties.  If I try to click back on the sound and audio devices properties window without clicking on cancel or okay in the audio codecs properties windows first, it beeps, which is telling me I have to close that window first.  I'm sure theres a technical term for this, but I'm not sure what it is.  Thanks.

I'm at a loss, this is the first time I've seen a post with this problem.  My E510 manual has the same info as the E310, nothing on the "beeper". 

My new E521 was driving me nuts with the beeping, too... after much web searching I came across this fix for the problem, although I can't remember where I found it:

Go into the registry (use regedit.exe), navigate to Hkey_current-user, then to Control Panel, then to Sound. Now, over in the right pane, you will see B eep and Extended Sounds listed, simply change (under the data column) yes to no for each one, and then exit the registry. Make a note to yourself on what you did so you can change it back if you ever want to.

srs/mn