I bought a second hand ARNOVA 10c G3. The previous owner had deleted the entire system, probably by making a factory reset. I am not getting any further than to the System Recovery. There is an option 'apply update from external storage'. But vol down does not function therefore I cannot try it.

I have downloaded the firmware update onto the PC (Windows 8.1), but I am not able to transfer the update file to the tablet.

In the settings appears a new device 'android' after connecting the tablet with the pc via USB. The properties of this device contain the option to access two additional removable drives. They are shown here as deactivated and shown in the explorer, where I also cannot access them. Instead I am getting an error message telling me to insert a disk.

I have inserted a SD card into the tablet, containing a copy of the firmware, this card also is not recognized.

This is my first contact with any android device. I spent an entire day googling and did not find a solution. Maybe here somebody has any idea, what I can do?