I also need to find a good PC repair program that will fix registry errors as well. I keep my machine in tip top shape. Meaning I defrag on a reg basis, clean up useless clutter from the internet and such, as well as scanning for errors.

Reason I'm asking is because I upgraded to the 64bit OS and accidentally wiped my backup drive clean... and installed windows on it even... lol yah I know there's programs out there that will recover lost data like that but its too late for that. I took a beginning IT class so yah I know that much. Once a file is overwritten there's no chance of getting it back.

Like I said though I'm looking for a compatible firewall, preferably anything but Zone Alarm. As well as a PC diagnostic program to find and fix registry errors

Rather than using a software firewall, go for a hardware one instead.
A lot of modern internet routers come bundled with excellent firewalls.

Have a look at this thread for a more indepth discussion on the subject Is there any 64bit firewall for XP? (http://www.pcreview.co.uk/forums/thread-1949225.php)