Adding a strong password to your PC is the best way to ensure that unauthorized users can access it. However, if someone can gain access to your PC while you are not there, there is a chance that they could try to guess the password. To slow them down a bit you can have Windows temporarily lock when an incorrect password is entered. This will limit the number of times they can try out a password before you return to the PC. To enable this feature, proceed as follows:

Click Start > All Programs > Accessories, right-click Command Prompt and choose Run as administrator (XP users just click Command Prompt).

Type net accounts /lockoutthreshold:3 and press [Enter]. This will set the lockout to activate if the password is incorrectly entered three times.

Type net accounts /lockoutduration:30 and press [Enter]. This will set the lockout to last for 30 minutes.



Type net accounts /lockoutwindow:30 and press [Enter]. This will allow your login to be reset after 30 minutes.
Type EXIT and press [Enter].


Source : tracker fourms