removing obsolete files in APT
 

I have installed Knoppix to the hard drive and have removed some packages that were on the CD that I no longer need. However, these packages still appear in the list of packages shown in Synaptic or Aptitude, and they are not found in Debian repositories. I have tried the "--purge" option to remove them, but they are still listed. Is there a way to remove obsolete files that still appear in the package list?

First check that there is nothing strange in the /etc/apt/sources.list that might contain the packages you want to get rid off.

Run 'apt-get update' to get lists up to date.

If there are configfiles hanging around with some packages (you can check this with a 'dpkg -l thepackage'. The state "rc" mean that there are conffiles hanging around), run 'dpkg --purge thepackage' to get rid of them.