Look in the case, there should be a small speaker.  Just unplug it from the motherboard.

Ahhh, well let's see....... If I were in this situation I believe I would unplug the speaker. If for whatever reason it was hardwired I would cut the wire(s).

Jeff :emotion-22:

Thank you for your reply. I was hoping for a solution that I could implement with having to open the case of 29 computers. If that is the only way, oh well.

You should research this further. Does the Optiplex have a separate or integrated sound card? The internal speakers are only for system beeps and alerts, not regular sounds--like Internet, sound schemes, etc. You have to attach speakers to the green sound port for sounds. Seems to me you don't have to cut or disable any wires.

Some of the commercial line desktops do have optional internal speakers, unlike the consumer line that does not.

It looks like whoever ordered them, ordered them with the optional internal speakers.

I agree with the others, open the case and disconnect the speaker.  It may be a hassle but they do get "permanently" disabled.

Thanks, I was not aware that business computers could be ordered with internal speakers. Too bad there is not a way to disable them without cutting wires.

[I do know it is late but...]

You'll not find any internal speaker (probably), but a "beep"; and you'll cannot cut the wires: it is soldered. Look for a black cylinder near the button battery: that is the "speaker" which beeps.

I cannot test it (I was loofing just for the opposite: my "beepers" never beep) but, in Windows 7, clicking over the speaker icon (at system tray) you can get the "mixer". There you can setup "speakers" and "system sounds" at different levels.

Sorry

RØ

I apologize for my simplified sentence: of course you are right. What I meant is:
"unless you explicitly have selected the optional internal speaker (380 has that option), you'll not find..."

And, as most of us try to cut budget...

Regards

RØ

P.S. I'm sorry: writing in English is somewhat tiring when you think in another language :emotion-42:

You'll not find any internal speaker (probably), but a "beep

SOME models of the commerical line systems DO have an option for internal speaker.  The Home/Consumer line PC's do not have this option. 

If you're running Microsoft Windows you can disable the Internal speaker or PC speaker by following the below steps.

1. Open Device Manager
2. In Device Manager click View and click "Show hidden devices"
3. This should make "Non-Plug and Play Drivers" visible in Device Manager.
4. Expand Non-Plug and Play Drivers by clicking the plus and double-click Beep.
5. Within the "Beep properties" window click the Driver tab.
6. Under the driver tab if you wish to temporarily disable this device click the Stop button. If you wish to permanently disable this device under the Startup type select Disabled.

Motherboard jumper

If following the above steps does not disable the Internal speaker you can also almost always disable the Internal speaker through jumpers on the motherboard. Many motherboard manufacturers have jumpers that when jumped or not jumped will enable the onboard speaker.

Unfortunately all motherboards are different, therefore you will need to refer to the motherboard documentation in order to determine if your motherboard has such a jumper and what to set it to.

Motherboard cable

Some motherboards do not have an onboard speaker and instead use a computer case speaker that can be removed to disable the speaker. Unfortunately again you will need to refer to the motherboard or computers documentation to determine if your computer is setup this way.