By default, the power options on a Windows XP-based portable computer are configured to save power by decreasing the brightness of the LCD screen. However, if you start the computer while it is running on battery power, the brightness of the LCD screen is the same as when the computer is running on alternating current (AC) power. Therefore, the computer consumes the battery power faster than expected.
This problem occurs only if you start the computer while it is running on battery power. If you unplug the power cord after the system is already running, the brightness of the LCD screen is decreased as expected. Additionally, this problem occurs only on computers that are equipped with certain chipsets.
A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing the problem described in this article. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.
If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, contact Microsoft Customer Service and Support to obtain the hotfix.
Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site:
Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.
To apply this hotfix, you must have Windows XP Service Pack 2 (SP2) or Windows XP Service Pack 3 (SP3) installed.
For more 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
You must restart the computer after you apply this hotfix.
Hotfix replacement information
This hotfix does not replace any other hotfixes.
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.
Windows XP with Service Pack 2, x86-based versions
Windows XP with Service Pack 3, x86-based versions
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
824684 Description of the standard terminology that is used to describe Microsoft software updates