When you have more than one ADB installation on a PC, you could have an ADB clash. This could cause ADB and other tools which use ADB (e.g MTK Droid Tools) not to work properly.
Setting up ADB is pretty easy, you could either use the ADB installer method @ https://forum.hovatek.com/thread-588.html or the PdaNet method @ https://forum.hovatek.com/thread-317.html .
Normally, to check if ADB is setup and working, you enable USB debugging on the phone (see https://forum.hovatek.com/thread-10109.html), connect the phone to PC (via USB cord) then run the command below:
You should have something like this as output:
If after setting up ADB, ADB sometimes detects your phone and sometimes doesn't, then you're likely looking at an ADB clash. An ADB clash could cause an empty list of devices attached as output ;
When you run the command below (which is supposed to refresh ADB):
the output will be something like * server not running *:
To investigate an ADB clash, run Task Manager (Ctrl+Alt+Del). You will find multiple adb processes running
You could locate the ADB.exe of each process by right-clicking and selecting Open file location
How to fix ADB clash
Ending the unwanted adb processes in Task manager might help but mostly not for long because the adb process would soon restart and the clash, resume.
To fix this error for good:
* If you installed ADB using the PdaNet method then ensure to exit PdaNet in the system tray (bottom-right corner) then uninstall it
* If you have more than one ADB folder then delete others so you have just one