Can't authorise android lenovo tablet in USB debugging mode

Question

I have Lenovo YOGA Tablet 2 830LC X86.

Rescue and Smart Assistant tool is a software to work with this tablet.
When i activate USB-Debugging in tablet i face the error below in Rescue and Smart Assistant tool.

Unauthorized is because after activating USB-Debugging mode in tablet and connecting my tablet to PC, there is no popup asking me if i want to trust this PC, which i have to agree (permanently).

By deleting the adbkey file found in C:\Users\[Username]\.android folder the permission dialog did n't appear on my device.

What should i do to fix this issue?

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Edit after comment :

1. I am using USB charging cable.
2. I have windows 7
3. USB OEM driver for Lenovo > When i connect lenovo tablet to pc a pop up shows up on pc to install usb driver.
   So i installed it & after that i can see tablet folders.
   But i did n't install any other things.
4. Have you reset the USB authorization on the device too (usually inside Developer options) > Is this your mean revoke USB debugging authorization? If yes i did it several times.
5. Is the device detected by ADB (call adb devices on command prompt)
   I found a adb.exe in this path : C:\MagicPlusMini\app
   After enter adb devices command it founds : Baytrail6F284E37 offline
   I found another adb.exe
   Here is the command prompt :
   C:\Program Files (x86)\Rescue and Smart Assistant>adb devices
List of devices attached adb server is out of date. killing...
daemon started successfully
Baytrail6F284E37 unauthorized

Answer 1

Resolution
Possible solutions if adb devices shows a device as unauthorized:

C:\Users\JohnDoo>adb devices
List of devices attached
17310D821D > unauthorized

1. Disconnect USB between PC and device
2. Stop adb server by entering adb kill-server in command window
3. On device use Revoke USB debugging authorizations in Developer Options
4. On PC delete adbkey file in user directory, for example C:\Users\JohnDoo\.android
5. Reconnect the device to the PC
6. Open a command window and enter adb devices. Watch the device's screen for any Authorization message and allow the connection.

The device should now show as device:

C:\Users\JohnDoo>adb devices
List of devices attached
17310D821D > device

If the above does not help, re-installing adb and or USB drivers may help.