"If you require a program that will prevent any other person from being able to access your computer, then this is the program you need." --PCWin

ScreenLock is unlocked via answering a question that you provide yourself and can change or edit at any time. For instance, you could make ScreenLock ask you "What is the meaning of life?". Your customized answer could be anything that comes to your mind. This makes it easy to remember your question, and virtually impossible for others to guess what the answer is.