Lots of USB devices need a mass storage device USB driver given its intermediate action between a USB stack and the SCSI (Small Computer System Interface) layer. The interface is not limited to computer systems only but it applies to lots of other devices. Thus, the mass storage device USB driver is used by lots of appliances such as external optical drives like DVD and CD readers, digital cameras, external magnetic hard drives, card readers, portable gaming systems, portable media players and lots of other digital audio devices, mobile phones and so on. When the mass storage device USB interface standard is met, the devices that support it are cataloged in the mass storage class.

While Windows 95 provided very little support for USB, with Windows 98, the mass storage device USB drivers started been widely available with Microsoft. Even if initially every USB storage device needed an adjacent driver, such drivers are now available for free download whenever a specific support for USB flash cards is needed. The domain is very complex and full comprehension of how Windows incorporates or gets compatible with mass storage device USB drives is for the IT specialists to achieve. The average user does not need specific technical information to be able to connect a flash memory card to a digital camera.

Just like with any auto-run features specific to removable or portable media, mass storage device USB cards are just as vulnerable to the infection with malware as any personal computer. The flash memory stick often becomes the entryway for computer viruses, leading to the infection of more systems. The user has no control when it comes to the protection of the USB drives. The simplicity and wide compatibility makes these devices very vulnerable. The best advice one can get is to avoid inserting a mass storage device USB stick into an untrusted computer unless there is a hardware read-only function.

The mass storage device USB interface does not work in combination with hard-drive based devices. The USB storage environment allows only functions of generic interface for the very simple read and write commands. This means that there are many limitations and dead ends when it comes to sending complex or device-specific commands to a mass storage device USB card. In time, experts will probably develop external disks that require no translation layer for intermediation, but until this becomes reality, we’ll have to manage with the memory flash drives we have.