Careless use of pen drives and other removable devices are one of the main reasons of virus infection. Because of the auto run feature of these devices, malware can easily get in to a computer by modifying the autorun file, so this tool has some vital importance.
As I said above, BitDefender USB immunizer has two sections. It immunizes the USB devices and SD cards. Therefore, even if your storage device has been plugged into an infected computer, the piece of malware will be unable to create its autorun.inf file, thus annihilating any chance of auto-launching itself.
The Immunize Computer slider allows you to toggle the autorun feature On or Off for any removable media (except for CD/DVD-ROM devices). If you accidentally plug in an infected USB drive that has not been immunized, the computer will not auto-execute the piece of malware located on the USB storage device.
Interested users can free download BitDefender USB immunizer at source here. [Similar tool: Panda USB Vaccine.]