APT/dpkg info file missing !!!

[Hamid <hrg27h@netscape.net>]

Hi
When was trying to install kdm by "apt-get install kdm" , my system 
froze and I had to push the reset button.
Now I want to get back to gdm (kdm keeps locking up my machine), but I 
get the following message:
"dpkg: failed to open package info file '/var/lib/dpkg/available' for 
reading: No such file or directory
 E: Sub-process /usr/bin/dpkg returned an error code (2)"

Does it mean I have to reinstall dpkg (which I do not know how) ?

Thanks
Hamid