If the computer is network connected, you can just install a base system and download applications from the internet. Also, the Sarge installer is much better see:
http://www.debian.org/devel/debian-installer/ or click here to download the netinst iso image:
http://cdimage.debian.org/pub/cdimag...86-netinst.iso That image is about 100 MB. If you boot the CD created by that image, it will guide you through installing.
You will likely not be able to run KDE on your system. You need about 256 MB of memory to get decent performance with KDE, 128 MB is a minimum I think. You should install fluxbox, icewm, or some other light window manager instead.