When the CD boots, you get to a screen with various options "Start/Install Ubuntu", "Start with safe graphics" etc. Have you tried "Check CD for defects" to see if the CD is OK ?
** Changed in: Ubuntu Status: Unconfirmed => Needs Info -- A downloaded CD hangs with "Adding live user" https://launchpad.net/bugs/51010 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs