Intelx86 Kubuntu install

[AJOHNSON73 at ec.rr.com]

This install is becoming a pain in the neck. 
I down loaded the ISO file from the web site and checked the MD5SUMS 
which matched perfectly. I then burned it onto a CD and booted off of 
it and started the install process. At the step of the installation of 
the packages it gives an error stating "unable to find bzip2..." and 
then it says there could be an error with the burning of the CD. I then 
burned another CD and it again gave the same error message.
I don't seem to see any problems during burning of the CD. I used Nero 
and a Lite-on SOHW writer.
I have now started installing Ubuntu. Can someone help me with steps on 
how to install Kubuntu from inside Ubuntu? I am new to this OS.

Thanks for your help.