I will describe the update procedure:
1) Download firmware Firmware 2.1.04.
https://files.ixnfo.com/Firmware/ARCHOS/firmware_a605.aos
2) Turn off the device and connect the cable to the computer.
3) Press the power button and when the logo appears, press TV/LCD.
4) Select “Format Disk” for complete cleaning or only “Repair Disk” for firmware upgrade.
5) Click done and wait a few seconds until a new disk appears in Windows Explorer.
6) Open this disk and copy the previously downloaded firmware file to it, also make sure that the System directory is empty.
7) Click “Repair Disk” on the device and done.
Done.