I tried to install Ubuntu 12.10 and Ubuntu 13.04 using Flash drive and DVD, but all times I get this error. What does it say? And how can I fix it?
Try booting again from CD, but this time press any key when the small logo appears at the bottom of your screen, to gain access to the advanced menu screen. Once you get to it, do Check disk for defect, and Test memory. That will tell you if there are any problems with hadware.
Also try verifying the ISO file, by running an MD5SUM on it, and try burning another CD/DVD at slower speed.