Go here and download the Ubuntu 8.10 Desktop
http://www.ubuntu.com/getubuntu/download
If the burned ISO file still does not run it may be a bad CD/DVD drive used to create the CDs or crappy media, it isn't uncommon. Burn the image at 8X or 12X speed and you may want to use Imageburn, a free CD / DVD / HD DVD / Blu-ray burning application.
http://www.imgburn.com/
If you want to play with Linux try installing it to a USB drive. It works faster than a bootable CDrom and does not disturb the installed OS.
This site is a great source:
http://www.pendrivelinux.com/
I used these instructions:
http://www.pendrivelinux.com/2008/04/09/usb-ubuntu-804-installation-from-windows/
YES! Imgburn! Probably the most accurate and accountable burning software out there, and it's frickin' free.
Been using it for years now on the winbows boxes.
Thanks GreenWolf70, I just downloaded PCLinuxOS and installed it on one of my old Compaq Prolinia DL380 servers. I could only get Ubuntu server or Windows Server to run on them until now. Now I can use them to run Folding@home and heat my garage too.
ImageBurn works, I like utilities that do one thing really well.
Well, apparently, running linux is a crime according to some teachers...
http://www.pcpro.co.uk/news/242520/teacher-threatens-to-call-the-cops-over-linux.html
She did relent,
http://www.pcpro.co.uk/news/243243/helios-and-linuxhating-teacher-kiss-and-make-up.html