Just one small point about the WinXP Firewall in case anyone has missed this (I haven't noticed a reference to this point and it is IMPORTANT!)
The WinXP firewall is fine. Does it's job. And provided you don't want to do the more unusual things on your computer using the internet, a LAN or whatever, it is a good firewall - hey! it comes with the package and sets itself up for you (in most cases).
However, it ONLY works on things trying to get INTO your computer. It does not even know about things going out. So it allows anything IN which you (or your programs) ASK for and tells everything else that your computer doesn't even exist (which is what you need hackers to be told).
So if you have avast! working and are absolutely sure that your computer is "clean", it is fine. But IF you should get a trojan horse and it goes active, THAT is now one of the programs running on your computer inside the firewall. So if IT sends information out (like the fact that your computer exists and what its IP address is) or even invites an unfriendly hacker in, the WinXP firewall does nothing about it. Hmmmm!
I am not bashing Microsoft and certainly not WinXP here. ANY firewall is a good idea rather than none. But if you have missed the point I made - or worse still, don't understand it (quite possible the way I wrote it) - and if you have a permanent connection (broadband etc), I strongly recommend you have a look at Steve Gibson's site and read up on it a bit (not too much though!

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You'll find it at
www.grc.com and it is the place I recommend you go to TEST your firewallespecially if you have one protecting a LAN (follow links to ShieldsUp! and yes, it is free). Also loads of info about firewalls and the results of their tests on firewalls - especially free versus paid-for ones (well, we avast! users LIKE it when someone recommends the free software because it is BETTER than the expensive ones, right?

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Hope this post is helpful - if not, I am sure the moderators will happily evict it

(Great site - great forum - keep up the good work)