Applebottom : Set your XP Firewall as described here: http://www.limewire.com/english/content/firewalls.shtml
As for your Norton package I'm not sure what it contains but it might be very wise to follow these instructions: Read the tips by Norm about Norton (click on link)

OK you're not very computer savvy, but this is hopefully the only time you'll need to worry about this! Once we get it right, you won't need to think about it again (with any luck.)

You must pay attention to all the details. Good luck!