Just to be a little more step-by-step for Miikerman’s suggestions.
For CHKDSK connect the unit, right-click, Propterties, Tools, Error-Checking.
For the firmware, use the Manual method in the firmware thread. Don’t install the Updater. Just download the firmware file, unzip it and drag it over to the SANSA CLIP driveletter.
To format: Settings/System Settings/Format.
