Free USB Guard is a simple tool which will warn you if you try to close down your PC, forgetting that there's a CD or DVD in the drive, or that you've a USB (or other external) drive connected.
And this can be a real time-saver. If you accidentally leave a DVD in the drive, for instance, you may then have to restart the system before you can eject and remove it. And if you're closing down someone else's PC and forget that you've plugged in a USB key, then you might easily wander off, leaving the drive behind.
Whatever the reason you want to use it, Free USB Guard is very straightforward. There's no installation required, just run the program and it stays active in the background. And if you close down or log off then the program checks for removable drives or leftover discs, displaying a suitable warning of anything it finds.
Of course this might be a nuisance in some situations. If this is your own PC, say, you probably won't care if you occasionally shut it down with a USB key connected. Right-click the program's system tray icon, though, and you'll find you can tell it exactly what you'd like to monitor, so you only get alerts which you actually want to see.
Overall, then, Free USB Guard is a handy and easy-to-use tool. Our only small problem with the program was its RAM use, which was typically around 27MB, a little more than we'd expect considering what it's doing.