Windows’ log-on password doesn’t actually secure your system, although in Windows 2000 it can secure files and folders. In other versions of Windows, it merely prevents people from logging on with your name. This is useful in business environments because it prevents a coworker from masquerading as you over a network, for example. But otherwise it’s really not much different from having no system security at all.

To keep people off your system entirely, you need a boot-up password. Most PCs let you create one through their setup menu. Setup varies from one computer to another, so I can’t give you exact instructions. Typically, pressing Delete soon after you turn on the computer–before it starts loading Windows–brings up the setup menu. If Delete doesn’t work, try Insert or Esc. Then search the various submenus of the setup menu until you find the password options.

Boot-up passwords aren’t perfect, however. Someone could still get on your computer while you’re logged on but away from your desk. To protect against this, password-protect either your screen saver or your system’s standby mode. If you use a screen saver, right-click the desktop, select Properties, and click the Screen Saver tab. Check Password protected and click OK. For standby or hibernate mode, right-click the desktop, select Properties, click the Screen Saver tab, and choose the Settings button in the Energy Star box. In the Power Options Properties dialog box, click the Advanced tab and then check Prompt for password when computer goes off standby or hibernate.

Now whenever your PC awakens from the screen saver or from standby or hibernate mode, you’ll have to re-enter your Windows password.