Hi jch02140,

For security knoppix mounts drives read only.

Assuming you have KDE desktop and boot from CD
then you must click on the drive icon to mount the drive.
Close the window by clicking the X
The desktop will show a green triangle indicating the
drive has been mounted.

Now you must change the read/write mode.
Right click -- for newer versions click on Actions
and then change read/write mode.

Older versions have a slightly different menu but
you should be able to find it.

Helpful hint -- when you post a question please give
a bit more information about your system.

Best Wishes
paradocs