Press the windows button together with r now type devmgmt.msc press enter. Now go to the display/view menu,select the option show/display hidden devices,now expand the networkadaptors section. Do you see an entry called BitDefender Firewall NDSIS Filter Driver? Double click on it and see if it’s enabled. If not enable it and press on ok. You may not see an exclamation mark. Now go to start,connect to show/display all connections now right click on each network you see and choose properties,select the BitDefender Firewall NDSIS Filter Driver entry and press on uninstall. After that download this BitDefender removal tool.. First right click on the red BitDefender icon near the system clock and press on exit. Now run the removal tool you will be asked to reboot your pc do that. Install BitDefender again.