Beginner. 7.2.0 installed as-is on USB key, via running live CD and flashing. Alles OK, except for disappearing window dressing, due to unsolved Compiz bug (I have to type "knoppix no3d" at every boot).

During apt-get installation of various AvidEmux dependencies, a concluding message told me that libc-2.17.so had been found in an unexpected location (UNIONFS/lib/i386-linux-gnu) and should be removed therefrom. So, I deleted the file, as told.

Begin(Nightmare):
I now have a crippled system, where everything from an "apt get" to an "ls" results in a can't-find error for libc.so.6 (which was in the same directory but was merely a pointer to libc-2.17.so). I could not even copy over a replacement from a CD. It seems that EVERYTHING RELIES ON THAT C-LIBRARY FILE. Finally with the system stuck (even net connectivity was lost), I rebooted it.

Now, the same error appears at booting, and Knoppix halts.

Examining that USB key from another running instance of Knoppix shows no UNIONFS directory on the problem key, where I may replace the C-library file. I tried copying it elsewhere, to no avail.

So, how do I remaster from the dead my USB key? It lacks only that one C-library file!

P.S. Remember, I'm a newbie. Please spell out any commands.