Is there anyway to disable/turn off the built in speakers in the motherboard. Because most of the time I use headphones with high volume. Sometimes it gets pulled out and disturbing others.
If the speaker itself is on the motherboard, then there's likely a setting in the bios to disable it.
If the speaker is part of the computer case, then you can simply disconnect the header connecting it to the motherboard.
In both cases your motherboard manual should have more specific information.
Why can't you simply mute the speakers?
Under Vista, click on the audio icon in the taskbar, then on Mixer, then select your speaker device in the Device menu (if not already displayed), finally click on Mute.