I have the same issue, the SENTIENT N72GU will not back up to the USB, there is no instructions on how to prepare the usb to receive the back up file, if this is required??
i need the footage in an ongoing case against the local police force, and require any advice on how to back up the information as i fear the cctv will stop functioning and i will loose all the footage once the police take it into there custody!!
Pleas can you confirm what i need to do to back up the footage to USB as soon as possible!!