The system is DELL laptop. So i am not sure if the cable of the internal PC speaker can be pulled. In preferences->sound->system beep, i unchecked the option "enable system beep". This solves the problem, but is there any way to change the system beep? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20101211/014ca815/attachment-0005.html>