In many cases, this can happen when the display settings are not correct for the display/monitor that you’re using. Many flat-panel LCD displays will only work with certain refresh rates, and setting a refresh rate outside this range can cause you to lose video. To remedy this, boot the computer in VGA mode and reset the display settings to your monitor’s optimum settings.
To boot in VGA mode, tap the F5 key repeatedly when you start the computer, until you see a screen that says “Windows Advanced Options Menu” at the top. This screen will offer you several boot options, including Safe Mode, Safe Mode with Networking, and several others. Among these choices will be an option for “Enable VGA Mode;” this is the option you’ll want to choose. Windows will set all display settings to their lowest values, which should bring your display back.