Important This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986 Description of the Microsoft Windows Registry
After you configure the energy-saving settings for an LCD monitor, the monitor on your Microsoft Windows XP Service Pack 1 (SP1)-based portable computer may not turn on again after you reopen the lid. For example, this problem may occur after you configure energy-saving settings by following these steps:
Click Start, and then click Control Panel.
In the Pick a Category window, click Performance and Maintenance, and then click Power Options.
In the Power Options Properties dialog box, click the Power Schemes tab, and then click After 1 min in the Turn off monitor list.
Click the Advanced tab, and then in the When I close the lid of my portable computer list, click Do nothing.
Click Apply, and then click OK.
Wait for one minute for the monitor to turn off. Close the lid of the portable computer, disconnect the computer from the power source, and then reopen the lid. The monitor may not automatically turn on as expected.
Note These steps apply when you have Control Panel set to Category View.
This problem is not resolved even after you press a key on the keyboard. In this scenario, you must restart your computer to regain use of the monitor.
This problem occurs because of an issue with the Videoprt.sys miniport driver and with the video graphics adapter (VGA) basic input/output system (BIOS) implementationin Windows XP SP1. When you open the lid of the portable computer in this scenario, the expected power request to turn on the LCD backlight does not occur.
To resolve this problem, obtain the latest service pack for Microsoft Windows XP. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
322389 How to obtain the latest Windows XP service pack
To work around this problem, add the following registry subkey:
To do this, follow these steps. Warning If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
Click Start, click Run, type regedit in the Open box, and then click OK.
Locate and then click the following registry subkey: