The software in a USB-based portable storage ... USB-based devices such as flash memory drives, memory card readers, digital cameras and external drives use this device class protocol.

A type of peripheral device that plugs into a USB port. Defined by the USB Implementers Forum, device classes provide the specifications for a standard set of drivers for common peripherals.

Read: USB Mass Storage Device driver not showing or working How do I get rid of power surge on USB port notification? If you get the Power surge notification, first of all, update your drivers.