I have looked through the forum as best I can and can't find a solution to my problem. I am trying to root my S4 and I keep getting "adb is not recognizable as internal or external command, operable program, or batch file" when I use motochopper. I have usb debugging checked on my phone. I have checked as best I know how for updated drivers. It says everything is up to date. When I hit enter on motochopper it says phone detected but over and over repeats that adb is not recognizable. I don't know what I am not doing. I have read forums that say I need to give my phone permission when it asks, but it never asks anything.

I have Windows 7, 64 bit on my computer.

Help!!!!