There's nothing particularly eye-catching about this free system utility, but it successfully performed its single function--to immediately lock and password-protect your computer.

Lock System can be activated by clicking on the desktop icon. During setup, you have to enter and confirm a password that will be used to lock your computer. To access the program's menu options and to actually lock your computer, you have to right-click on its taskbar icon. A hot-key combination would have been more convenient. Settings options are few, and include changing your password and running the program when you start Windows. Still, we were able to lock our computer as promised, although we were slightly annoyed by the banner ad displayed on the black screen that replaced the active desktop. We tried to see if we could end the program using our Task Manager, but we were pleasantly surprised to find that it didn't appear on the list. Access to the computer was easily restored by entering the password in a field on the black screen.

Lock System worked exactly as promised, and if you don't mind the unappealing design and basic features, it's worth giving this program a shot if you just want a quick way to lock up your computer.