Is Winsock different for Firefox Portable?

After removing malware ("Internet Antivirus Pro") from a friend's computer (XP SP3), the winsock catalog reported errors, which I understand is not uncommon. I've run half a dozen repair utilities, followed the manual instructions from Microsoft and third-party sites, and spent about six hours researching.

IE7, IE8, and FF3 are all unable to access HTTP (although HTTPS and FTP work), but Firefox Mobile runs just fine.

Does this indicate any kind of next step to anyone? What about Mobile bypasses the error?

Thanks,
-Magellan