Hmm…Interesting that Adobe told you to install PPRO 1.5.1 over the standard one. Uninstall all versions of Premiere Pro you have on your system and then download a program called CrapCleaner. Fix all issues that it comes up with and then reinstall the retail version only (the latest one).
Looks like you are having 2 problems: Freezing computer and DVD problems. I would suggest a complete reformat of the system and then installing only Premiere Pro to see if the problems go away or not.