So I go to put knoppix on an old (2001) gateway computer with no current operating system on it. I get an error message that says
Unfortunately, the device system:/media/hdc (/dev/hdc) named 'KNOPPIX' and currently mounted at /cdrom could not be unmounted. The following error was returned by umount command:
umount: /cdrom is not the fstab (and you are not root)

How do I fix this?

I also get a KDesktop - The KDE Crash Handler message. It says

The application KDesktop (kdesktop) crashed and caused the signal 6 (SIGABRT).

Sorry for the questions, its late, I'm tired and I just want this thing to work.