Error : The connection to adb is down, and a severe error has occured.

Getting Error:

>The connection to adb is down, and a severe error has occured.
>You must restart adb and Eclipse.
>Please ensure that adb is correctly located at 'C:\Android\android-sdk-windows\platform-tools\adb.exe' and can be executed.
>Daemon not running.ADB server didn't ACK

1. Go to the platform-tools directory:(you can find where you have AVD Manager.exe or SDK Manager.exe)
or in some paths given below:
Path 1 : C:\Android\android-sdk-windows\platform-tools>
Path 2 : C:\Program files\Android\android-sdk-windows\platform-tools>
Path 3 : C:\Program files(x86)\Android\android-sdk-windows\platform-tools>

 

2. Now check you have adb.exe present.

3. Now you need to have proper "android-sdk" normally it can never be absent.
    As it will be definitely there so open you terminal ( LINUX / UBUNTU users ) or command    prompt/ cmd ( Windows users ) and go to the above path where you have adb.exe:
cd\
cd C:\Android\android-sdk-windows\platform-tools [ or your adb.exe path ]
Now, use following two command:
adb kill-server
adb start-server
[ you can use this commands when Eclipse closed or open; if it doesn't work when your eclipse is open do it after closing eclipse. ]

NOTE: you can also end or kill process of adb.exe from task manager.

in Windows, just use task manager to kill the process.

 And Restart Eclipse.