[newbie] Installation Problem

[David Brown]

I'm installing Linux Mandrake 7.0 on a clean hard drive auto allocated for
linux.
During the install, I choose what packages to install.  If I choose to
install the KDE GUI,
when the system reboots I get an error,

KDM: error in loading shared libraries: libz.so.1: cannot open shared object
file: no such file or directory

If I choose to install the gnome GUI instead, I get the same error after
reboot except that it is GDM instead of KDM.

Please help...

David