Wireless Disappeared From The Network Manager

to enable wireless that disappeared from the network manager we only need to do some little thing

1. Open terminal

2. Type

cd /etc/NetworkManager/

sudo gedit nm-system-settings.conf

3. text editor gpedit will open

4.  Change "managed = false" to "managed = true"

and then restart Network Manager

sudo /etc/init.d/networking restart

 and restart the ubuntu.