The 1394 connection is firewire, which I doubt you are using.
You need to use the fast ethernet connection.
The Windows Firewall is part of XP - SP2 only turned it on by default. It was part of XP since the beginning.
By uninstalling SP2 you have exposed your computer to exploits too numerous to mention. Your inability to use IMs and games had nothing to do with SP2 but rather with your security settings, antivirus and/or anti-malware settings, etc.
Have you checked for malware - and what did you use to check for it?
The first thing you need to do is to try to run the following. I don't know if it will run without SP2 though, and you can't reinstall SP2 until you know your computer is free of malware. Try it.
Windows One Care Free Scan
Go to Windows Live Onecare Free Scan
It will say "Get a free PC safety scan"http://safety.live.com/site/en-us/default.htm
Make sure you click "Full Service Scan"
in the middle of the page and not the "Try It Now Free" on the right side.
Allow it to download an Active X component.
Choose "Complete Scan" in the window that opens
Do not click on anything else that offers you a free trial or to sign up if you live in the US.
Allow it to scan - it may take quite a while, maybe two hours or so depending on how big your hard drive is and how fragmented your registry and drive are.
If it finds any malware other than cookies you should post a HJT log but lets see what the scan finds.
Let us know.