When Predator's monitoring is active, it places an icon in the system tray that lets users Pause or Edit the program, view log files, and access the Preferences, which include password and encryption key tools, alarm options, and Advanced options, including the ability to enable Twitter-based logging. To set up the program, you need to create a password and a security key, but it's easy to do. Predator Free is available in separate downloads for 32- and 64-bit versions of Windows. If you lose your USB drive or don't have it handy, you can still unlock your PC with your password. It also logs activity and can sound an optional alarm. You can enable passwords for every operation or just once, which adds convenience if you're often away from your desk. When your thumbdrive is removed, Predator locks your PC and darkens your screen if anyone tried to use it without entering the password. This free security tool locks and unlocks your PC when you remove or insert a USB drive. If you leave your PC unattended and running in a public area, how do you keep people from using it? You have several options, but one of the easiest we've tried is Predator Free.