Reboot into Safe Mode (boot loop may occur, the device may become unresponsive)
If all else fails, you can try to re-install Android OS. Simply go into Settings->Restart & Update System and select Restart Now. Reset Zong 4G WiFi Device.
Precautions
Do not attempt this without backup of the device.
Attempting to perform this action while the device is turned off and the battery is disconnected could potentially brick it.
It is highly advised that you use a USB cable when backing up the data to prevent data loss.
Monitoring your PC for Android device updates
If you are already using the Android Device Manager, you can check on your device’s status by using the Android updater.
Add your phone to the Android updater. If you are on the latest version of Android and your device’s software version is above 6.12, your device is ready to be updated.
If not, go to Settings->Security->App Ops->Android updater. In the Security app, tap ‘Check for updates.’
Select “Ok” and let the updates begin. When the Android updater process is complete, tap ‘Done’ to end the installation.
Enabling USB debugging on your PC
Performing a Windows PC hard reset to hard-enable USB Debugging will also enable USB debugging on your device.
If your phone is updated and working, you can access the following settings from Settings->Advanced Features->USB debugging.
Settings->Devices->Devices Settings->Network (number of devices you are paired with), and Change the USB setting to ‘Send and receive’ by tapping on the corresponding button.