Since a lot of people work in runlevel 3 the previous tip may not work.
So I’ve searched for other solutions found another way of disabling system beep (on tab completion).
Just edit /etc/inputrc
and uncomment following line:
# do not bell on tab-completion
set bell-style none
Then after next login system beep on tab completion will be disabled system-wide.
And another one:
as root type:
This one will remove the module responsible for playing sound on system speaker.
Should disable the module too, but it is not working for me under CentOS 5 – submitted as bug.
Another one (Hardware):
If you have PC simply open the case and unplug speaker cable from the motherboard.
NOTE: PC speaker could be very usefull when troubleshooting problems so this option is not really recommended.
OR search in your BIOS for option to disable it.