I've seen the WMI get corrupted and caused an issue from preventing you to access the setting. Not sure what you can do for that, except for maybe reinstalling the service pack or a repair. It could be possible that what ever is corrupted is related to your connection issues.
As for turning off the firewall, go to your start menu > then go to run > then type in: netsh firewall set opmode disable
That will disable your firewall, you can change it to enable if you want it back on.