'adb' is not recognized as an internal or external command, operable program or batch file

Set the path of adb into System Variables. You can find adb in "ADT Bundle/sdk/platform-tools" Set the path and restart the cmd n then try again.

Or

You can also goto the dir where adb.exe is located and do the same thing if you don't wanna set the PATH.

If you wanna see all the paths, just do

echo %PATH%

From Android Studio 1.3, the ADB location is at:

C:\Users\USERNAME\AppData\Local\Android\sdk\platform-tools.

Now add this location to the end of PATH of environment variables. Eg:

;C:\Users\USERNAME\AppData\Local\Android\sdk\platform-tools