Step 1) What is your PC's storage devices?
Mine is:
hda = 160GB IDE HD
hdb = 80GB IDE HD
hdc = DVDROM drive
hdd = CDRW drive
Either you might know it off the top of your head or you can run commands and get the output.
Code:
dmesg | grep -i hd
dmesg | grep -i ide
Step 2) You mentioned you installed Knoppix. Usually that phrase indicates that it was installed to a hardrive. Which hard drive & partition did you install to?