Start your system using the CD, This allows you to work on your system
and back up anything you may need to. Not knowing what you did it
makes it hard for anyone to help without studying your puter first
hand. Because you have allready started with a re-install you may as
well continue, or at least that is how I look at it, no telling what
files have been damaged.

A recap:
1. use the CD to start the system.
2. Backup your saved directories to CD or removable media.
3.Make a fresh install, but before you do make sure all the settings
you have made to make your system special to you are saved if you can
find them.

Like others say this is extreme, but then you have already taken some
of these steps before you asked.