SYSTEM PROBLEM CAUSED BY FIREWALLS?

On startup my Dsl Connection automatically connects tries to connect my computer slows down and crashes. Also when internet explorer is opened the system crashes. It all started happening when these programs were installed then removed.

I have installed 3 firewalls/ Programs :
Wyvern firewall 2004
ZoneAlarm Firewall
and Netveda Safety.Net 3.610002

Ive uninstalled all of em (But some files maybe be hidden still in my system which i cant get rid off).

However when my computer starts up with the DSL wire disconnected the computer works fine, but when it is connected again the computer loses its memory and begins to slowdown leading to a crash of the system.

I looked for every new file that was created when the programs were installed and it seemed netveda and wyvern still had a few files still on my system which werent deleted in the uninstallation, also my connection also has a new driver which was never there before "network monitor driver" which states that its a "netmon packet driver that allows the Netmon UI to acquire packets from the local network".

Im not sure if this is the problem but i have tried uninstalling it but it always leads to a system crash.

If anyone could help it would be much appreciated!!
Im currently running:
Windows XP service pack 2
Norton antivirus 2006

I've had so many issues in the last year with McAffee and Norton security suites really loading down computers until they performed worse than 3-year old computers without these suites installed that as a first step I'd try uninstalling Norton and running a lean AV like AVG for a try.