I used Internet Explorer to Diagnose Connection problems and in told me that his Winsock settings had been modified. I used WinsockxpFix as well as the command prompt to reset his winsock settings. When I run Diagnose Connection Problems now, the winsock settings error message has been removed, and replaced with a "Contact the company that provides you with Windows XP Product Support."
Obviously, this doesn't help me figure out what's wrong, or help others. I'm pretty much stuck at this point. I really don't know what to do. Any help would be greatly appreciated!