USB Flash Drive is a free tool which protects your pen drive from autorun viruses, it creates a undeletable write-protected dummy "autorun.inf" in the root folder in your pen drive, in this way it stops the creation of virus autorun.inf which causes the virus to get activated when you double click to open the USB pen drive under my computer.
Here is how you can protect your flash pen drive with this tool from trojans and viruses
1. First backup all the contents of the pen drive
2. Download and Install Flash USB Drive Protector
3. Run Flash USB Drive Protector and select the USB drive which you want to protect.
4. click Protect button after selecting the USB drive.