Article ID: 833740
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:
(http://support.microsoft.com/kb/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:
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) implementation in 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:
(http://support.microsoft.com/kb/322389/EN-US/ )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.
(http://support.microsoft.com/kb/823348/ )INFO: The monitor may not turn on after you configure the energy-saving settings on some portable computers
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Microsoft Windows XP Service Pack 2.
For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/824684/ )Description of the standard terminology that is used to describe Microsoft software updates