How can I open the USB Debugging Mode?

To open the USB Debugging Mode on Android correctly, you should follow it below according to your Android OS:

For Android 4.2 or later
1. Find Settings on device.
2. Click About Device.
3. Find Build Number and tap it for 7 times continuously.
4. Go back to Settings and click Developer Options.
5. Check USB Debugging Mode.

For Android 3.0 - 4.1
1. Find Settings on device.
2. Click Developer Options.
3. Check USB Debugging Mode.

For Android 2.3 or earlier
1. Find "Settings" on the Device.
2. Click "Application".
3. Click "Development".
4. Check USB Debugging Mode.

Related Article:

How to Enable USB Debugging on Android Phone