installation freezes up

[jdubs]

when I go to boot from a cd or usb the installation always freezes at the point where those 5 dots are, both for installation and "just trying", any ideas on what i should do?

[fantab]

First of all check the integrity of your dowloaded.iso by using md5sum check (https://help.ubuntu.com/community/HowToMD5SUM).