Network Manager Error : Device not managed (ubuntu)

I am facing the problem with Network Manager shows  error, with Wired and Wireless connection. When I click on  tetwork connection, It show "device not managed".

Problem Solve :

> First run command on terminal to see the connection status  sudo  lshw -C Network 

 This show ouput like :

sudo lshw -C network

[sudo] password for jagdeep: 

  *-network DISABLED               

       description: Wireless interface

       product: Centrino Wireless-N 1000

       vendor: Intel Corporation

       physical id: 0

       bus info: pci@0000:03:00.0

       logical name: wlan0

       version: 00

       serial: 8c:a9:82:5e:e4:e2

       width: 64 bits

       clock: 33MHz

       capabilities: pm msi pciexpress bus_master cap_list ethernet physical wireless

       configuration: broadcast=yes driver=iwlagn driverversion=2.6.38-8-generic firmware=128.50.3.1 build 13488 ip=192.168.1.34 latency=0 link=yes multicast=yes wireless=IEEE 802.11bgn

       resources: irq:41 memory:f0500000-f0501fff

  *-network DISABLED

       description: Ethernet interface

       product: AR8152 v1.1 Fast Ethernet

       vendor: Atheros Communications

       physical id: 0

       bus info: pci@0000:04:00.0

       logical name: eth0

       version: c1

       serial: 14:fe:b5:9a:33:ba

       capacity: 100Mbit/s

       width: 64 bits

       clock: 33MHz

       capabilities: pm msi pciexpress vpd bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd autonegotiation

       configuration: autonegotiation=on broadcast=yes driver=atl1c driverversion=1.0.1.0-NAPI firmware=N/A latency=0 link=no multicast=yes port=twisted pair

       resources: irq:44 memory:f0400000-f043ffff ioport:2000(size=128)

> If it Show connection is DISABLED than you need to edit following file /etc/NetworkManager/NetworkManager.conf or /etc/NetworkManager/nm-system-settings.conf

Code :

[main]

plugins=ifupdown, keyfile

[ifupdown]

managed=false

> Changing managed=false to managed=true if  You want NM to manage

> Now back in the terminal type sudo killall nm-system-settings or  sudo killall NetworkManger.

It works.

Some Basic Network Commands

 $sudo /etc/init.d/networking restart

 $ping google.com

 $plog

 $ifconfig

 $

sudo pppoeconf (For setting Dail up Connection with username and password)

 $

lsusb

 $lspci

 $lsmod

$iwlist

 $sudo iwlist eth0 scan

 $sudo lshw -C network

 $rfkill list all

 $rfkill unblock all

 $sudo /etc/init.d/networking restart