when i type

Code:
dmesg|grep sr
nothing happens it just shows

Code:
root@mybox:/home/knoppix#
also im sorry , but i forgot to mention im using the grub bootloader, here is my grub.conf

Code:
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,1)
#          kernel /vmlinuz-version ro root=/dev/hda3
#          initrd /initrd-version.img
#boot=/dev/hda
default=2
timeout=10
splashimage=(hd0,1)/grub/splash.xpm.gz
title WindowsXP
	rootnoverify (hd0,0)
	chainloader +1
title Knoppix
	root (hd0,2)
	kernel /vmlinuz ro root=/dev/hda3
when i type

Code:
dmesg|grep sr
i get nothing, so i added what you said to the grub.conf, and still nothing.

more help will be appreciated