I was having a problem with my Win XP PC that it could no longer connect to the internet, the below explains how I resolved this. Problem description; http://www.techzonez.com/forums/showthread.php?t=20718

Hi, I'm having a problem with my computer and help would be greatly appreciated. The problem is that when I log in, it sits for at least 2 minutes with the desktop background displayed before loading everything up. It then displays an error saying:

"An existing critical communications file (C:\WINDOWS\system32\WS2_32.dll) is either old or invalid. Microsoft ActiveSync cannot establish a connection with the mobile device until this file has been replaced".

This is exactly what I was getting, it seemed to result from installing some mobile development software - though the google results seem to indicate this is related to malware.

Quite wonderfully I found the instructions on how to fix it;

http://www2.cit.cornell.edu/security/spyware/WinFix/pictures.html

And download the software here;

http://www.spychecker.com/program/winsockxpfix.html

The process was very simple didn't take very long, and after completion the network and internet worked again perfectly.