Well... Firewalls arent really 100% protection for your computer... One way of hacking into a computer that has a firewall is to first know what firewall they are using.. I think there is such software that would do that.. second.. you can also exploit one Win2k vulnerability which is the file sharing default.. once you manage to get into the c: drive.. you can then have a look around what firewall the person has.. then leave a batch file on the start up menu and program that batch file to delete the firewall.. when the person starts the puter.. the batch file will then execute and delete the firewall..

anotherway is when you get inside.. firewalls have a certain .ini file that tells the firewall which ports to block.. elite crackers would edit that file and leave one port open as a back d00r..

or.. once you find out what the firewall is.. you can search for an exploit for it.. piece of cake..