Start with an empty Flash Drive. Download and install TrueCrypt from www.truecrypt.org Click ‘create volume’ to create a standard TrueCrypt volume. Click ‘select device’ – choose your USB flash drive, click it, then choose OK.
Click ‘next’ to see the encryption options (algorithms) you can use, click ‘next’ to accept the volume size, then enter a password. (Make sure its something easy for you to remember, yet virtually impossible for others to guess!)
Move your mouse over the ‘next dialogue’ to set a random starting point for the TrueCrypt encryption, then click ‘format’ to format the flash drive. (If you have any preexisting data on the flash drive copy it to your hard-drive right now).
To access the Flash Drive click ‘select device’ in TrueCrypt and chose the flash drive. Select ‘mount’ enter your password and the Flash Drive will now appear in explorer Click ‘dismount’ to remove the drive.
You have now password protected (and encrypted) your USB Flash Drive to stop others from accessing your sensitive data.