Off and disabled are two different things. If you turn it off in Control Panel it is exactly that Off (as in not filtering traffic) If you want to disable it completely you need to disable the service. Start > Type services.msc, locate Windows Firewall stop the service and set it to disabled. If you have no other firewall running though I would highly recommend leaving it on.
The Work, Private and Public profiles are linked directly to the Windows Firewall. Each profile has different firewall rules associated to it. So when you first connect to a network you would select the appropriate provide.