If in your computer the instrument appears as “unknown device” and you are not able to enter, it could be necessary to repair and restore the USB memory.
press the right button of the mouse and choose the option format at FAT32
enter in the “Configuration Menu” and scroll the menu: at the end you will find the buttons for formatting the USB or/and the internal memory. Just press it and confirm.
Note that the Instrument’s settings and files are reported to the original manufacturing: It is important to have a backup of personal files!