: Use a reliable USB cable to avoid connection drops during data transfer.

Select "Firmware Upgrade" in the dropdown menu (Do not choose "Format All + Download" unless necessary). Click the Download button (green arrow). Switch off your Oppo F1s.

Right-click on the driver installer configuration file (often Install.bat or cdc-acm.inf ) and choose .

: Ensure the drop-down menu is set to "Download Only" (Do not use Format All + Download as it deletes vital IMEI data).

: The PC fails to recognize the phone. Reinstall the MTK VCOM drivers, try a different USB port (preferably USB 2.0), or use a different cable.