Why does ClassMate Reader not recognize my SD card?
If you have an SD card which is not recognized or which results in many media errors you should format it. Although most commercial cards come pre-formatted it may be possible the formatting was not done correctly. To format, insert the SD card into your PC card reader. Open the ‘My Computer’ program from your desktop and right-click (or press the Applications key on your keyboard) to bring up the context menu for the SD card. Select ‘Format’ from this menu.