Need help from computer-savvy DUers.

[playahata1]

Something called a "Trojan horse" -- plus some other crap -- has been trying to attack my computer all day. So far my security system has been effective in blocking it, but the bastard keeps coming up.

I've only had home internet service since March; while there have been previous hacking attempts on my computer (I didn't get Sasser-ized, though), this is the first time I've been bombarded like this, and I know I need to update my security (Norton 2002). What's the most effective internet security system out there? Thanks.