Lock and Unlock Your PC With USB Drive Software - Version 7.0 This software offers a solution to users who want to lock their computer using a USB device as a physical key instead of a password. Each USB device has a unique identity and with this software it can be used as a key. Simply insert a flash drive into the computer then select that drive from the dropdown list, click start and remove the USB device. The computer is then locked until the same drive is inserted again. This easy to use software provides easy and sure security against others using your computer while you are away.