well you might not want o take it of but modify what it blocks usually there is an icon of the firewall within the box where the time is look for any icons you do not know of and try dooble clicking on it to figure out what it is. If you have Norton open Norton System works and there should be a heading in the left column saying Norton firewall. You might also want to ask the person that put the firewall in there which one it is. and maybe contact your internet compagnie or modem compagnie to know if they put a build in firewall the modem or if the service provides one.

when you find out which one you have say it on this forum so I or someone else may help you.