What’s one of the most common ways to get unauthorized access to someone else’s computer – especially that of a friend or family member? By guessing the password!
Someone who knows you well may be able to figure out your password, especially if he can try different possibilities before hitting on the right one.
If you’re running Windows 7 Professional, Enterprise or Ultimate edition (or the equivalent edition of Vista), you can set your Windows account to temporary lock if someone enters the wrong password several times in a row.