I have been told that the built in firewall is set to microshafts rules.And not to use it.But to each his own.I have used Nortons internet security F/W and when its set to high got warnings that my server was checking my ports with a keylogger !! But when set to default didnt get the keylogger warning.Most F/W are like a pmsing woman ,touchy as all heck when messed with!So best leave the devil sleeping.