so you can get on all other web pages just not facebook? is this at home or work? do you have a router? do you have a firewall software installed (ie: zonealarm)? can't give definitive answers without complete info, if it's at work, blocked by administrator to prevent people from screwing around, if at home, then router firewall can block you, no router then software firewall blocking you or a security certificate was created to block that site specifically, only the one who made it can remove it.