Hi I have knoppix 3.9 installed to an extra partition to have a peek at Debian, and the kernel is 6.11, my system is a dfi board with an Athalon xp3200, and a hp dvd writer and a pioneer dvd rom. Knoppix recognized these drives running from the cd and they are there on the desktop running from the hard disc, but if a cd is opened an error message of cannot open//mnt/cdrom file path does not exist. I also run Suse pro on another hard disc on the same machine and it has no problems with either of the drives. I am a Linux novice, any help is appreciated.

My first thought would be that the /mnt/cdrom path hasn't been created yet. Linux mounts your various drives into directories, but these directories have to already be there and be empty.

Here's a step by-step on how to do it (It sounds complicated, but let's go ahead and do it a way I know will work):
1. First of all, look for the folder. Open up your file browser and just look for /mnt/cdrom. If it's there, then you might as well ignore the rest of this since this isn't your problem.
2. If the folder isn't there, then open up a terminal (there should be an icon on the taskbar or its menu for it).
3. First type su and put in your root password (this is to make sure the directory's available to everyone); if you don't know the root password...you'll have to figure it out. If you haven't set one up, it might be blank or some special keyword, such as "root", "admin", or "knoppix" - it shouldn't be hard to find the answer. (Actually, look under the Knoppix menu, I think there's an option to change the root password there)
4. Once you're root, cd to / ("cd /")- is the mnt dir there? If not, type "mkdir mnt".
5. cd into the mnt directory ("cd mnt") and then do "mkdir cdrom".
6. That should do it; but since you have two drives, you might have to do this all again for the second drive; just load up a disk in it and see if you get a similar error with a different path; if so, just do all this for that path too.

I hope this helped; I haven't used Knoppix for more than about 5 minutes, but from the sound of things this should fix the problem.

It dosen't show up in konqueror when i type /mnt/cdrom, however it is there when i type in / and open the /mnt folder, but no files are in either drive then i open either cdrom or cdrom1 folders though a cd is in each drive. This is what is displayed in the terminal window.

randy@Nix:~$ su
Password:
root@Nix:/home/randy# cd /
root@Nix:/# mkdir mnt
mkdir: cannot create directory `mnt': File exists
root@Nix:/# cd mnt
root@Nix:/mnt# mkdir cdrom
mkdir: cannot create directory `cdrom': File exists
root@Nix:/mnt# mkdir cdrom1
mkdir: cannot create directory `cdrom1': File exists
root@Nix:/mnt#

And this is what I get trying to open the cd icons on the desktop.
unable to run the specified comand the file://mnt/cdrom dose not exist.

You are likely right it is some other problem, But thank you for the help though it hasn't solved my problem i have learned some more.
This is my /etc/fstab file The last time I have used it was with red hat 9 to mount my fat partitions at boot is there any thing i can change there to mount these drives, the floppy is the same way.

# /etc/fstab: filesystem table.
#
# filesystem mountpoint type options dump pass
/dev/hda7 / ext3 defaults,errors=remount-ro 0 1

proc /proc proc defaults 0 0
/dev/fd0 /floppy vfat defaults,user,noauto,showexec,umask=022 0 0
usbfs /proc/bus/usb usbfs devmode=0666 0 0
sysfs /sys sysfs defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
/dev/cdrom /cdrom iso9660 defaults,ro,users,noexec,noauto 0 0
/dev/cdrom1 /cdrom1 iso9660 defaults,ro,users,noexec,noauto 0 0
/dev/dvd /dvd iso9660 defaults,ro,users,noexec,noauto 0 0
# Added by KNOPPIX
/dev/hda1 /mnt/hda1 ntfs noauto,users,exec,ro,umask=000 0 0
# Added by KNOPPIX
/dev/hda5 /mnt/hda5 vfat noauto,users,exec,umask=000 0 0
# Added by KNOPPIX
/dev/hda6 /mnt/hda6 vfat noauto,users,exec,umask=000 0 0
# Added by KNOPPIX
/dev/hdb1 /mnt/hdb1 ntfs noauto,users,exec,ro,umask=000 0 0
# Added by KNOPPIX
/dev/hdb5 none swap defaults 0 0
# Added by KNOPPIX
/dev/hdb6 /mnt/hdb6 vfat noauto,users,exec,umask=000 0 0
# Added by KNOPPIX
/dev/hdb7 /mnt/hdb7 ntfs noauto,users,exec,ro,umask=000 0 0
# Added by KNOPPIX
/dev/hdb8 /mnt/hdb8 auto noauto,users,exec 0 0

Any help is appreciated and thanks again.

Try changing those three lines to this:
In case you couldn't tell, I changed the folders to be /mnt/cdrom, /mnt/cdrom1, and /mnt/dvd instead of /cdrom, /cdrom1, and /dvd. You might not want to change the dvd line, because you haven't mentioned that, but if you do have a third drive in there, it's probably going to come up there, too.

No just thev 2 dvd drives, I think it is something amis with the install, updates or some other app conflicting with something else or knoppix 3.9 ,don,t know .I changed the lines but to no avail, will try a reinstall, 3.8 had no ill effects.

I hate to say it, but I don't know what to do...sorry, I'm by far no expert in setting up Linux, I just know what I've needed to learn so far.

Same here sir, I do however appreciate the help thanks, I am thinking it is a knoppix problem. It was installed on my partition I use to try differn't distros so it is not a mater of loosing data or anything. I am now playing with Xandros 3 from a dvd that comes with the July issue of Linux Magazine, it is impressive but I do not think I would pay for it.