Testosterone boy said:
Can't one just get a $400 router or something?
You have to think layers of defense. Some easy steps for you...
Router/NAT device - the external and first layer.
Software firewall on computer - Zone alarm, etc.
Don't use software that says "fuck me" to script kiddies. In other words... dont' use Internet Explorer and Microsoft Outlook/Outlook Express. Use Mozilla Firefox and Thunderbird instead.
Anti-virus software - Norton, etc.
At this point, for your level, you've put up a good passive/ semi-active defense.
Now, don't do anything stupid to let bad software install itself.
All can easily be subverted if malicious code is easy to run on your system.
DON'T RUN A LOGIN THAT HAS ADMIN PERMISSIONS.
Step through the link - create an XP login that doesn't have admin permissions.
WHY? Because software will not easily install if it isn't run with Admin permissions.
You don't do these things.... expect to be zombied real effin quick.