If you messed up your xorg.conf to the point where you can't get KDE, an option is to start over with the original configuration that did work. From the command line as root, get into the directory where xorg.conf is:
(Press 'enter' after each command) Then, to see what's there:
You should see two files (among others), one being xorg.conf and another xorg.conf~. xorg.conf is the file you are now having problems with. The original file you had before is xorg.conf~. We have to go back to the original file. You do this by renaming your old xorg.conf~ to xorg.conf...
Code:
mv xorg.conf~ xorg.conf
Don't forget to put a space between xorg.conf~ and xorg.conf. Then proceed into KDE as usual.
By the way, you might want to have a look at
Slapt-get. It essentially works the same as apt-get for Debian. Slapt-get is a good way to install new packages and it checks and solves dependencies. It's also good for keeping your box updated.