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Article ID: 940566 - Last Review: January 16, 2015 - Revision: 3.0

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This article has been archived. It is offered "as is" and will no longer be updated.

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Consider the following scenario:
  • You are running a Windows XP Service Pack 2 (SP2)-based computer that has an Intel Penryn processor.

    Note The Intel Penryn processor has a new power-management state that significantly reduces the power that is used by the processor during idle periods.
  • You let the computer become idle.
In this scenario, the processor cannot efficiently enter the new power-management state as expected.


The mobile Penryn processor has advanced power-management functionality that is known as Deep Power Down technology. Because Deep Power Down technology significantly reduces the power that is used by the processor during idle periods, a portable computer's battery life is extended significantly. However, on a Windows XP SP2-based computer that has a Penryn processor, the system does not efficiently enable this new power-management functionality during idle periods.


Hotfix information

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 this specific problem. 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 installed. For more information about how to obtain the latest Windows XP service pack, click the following article number to view the article in the Microsoft Knowledge Base:
322389  ( ) How to obtain the latest Windows XP service pack

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

File information

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.
Collapse this tableExpand this table
File nameFile versionFile sizeDateTimePlatform


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

More information

The Advanced Configuration and Power Interface (ACPI) specification describes processor idle power states as ACPI C-states. When the computer is in an idle state, Windows XP SP2 fully supports ACPI C-states by directing the processor to a low power idle state. Deep Power Down technology represents a recent advancement in processor idle states. This technology may also be recognized by the platform as the ACPI C6 processor power state. This new processor power state must be specifically enabled to work efficiently in Windows XP SP2. This hotfix implements that functionality.

Note If you use Windows Vista, you can visit the following Microsoft Web page for help with power consumption and battery life problems:
Fix problems in which power consumption is more than expected or the battery life is short (
For the more information about Intel Penryn processor, visit the following Intel Web site: (
Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.
The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.

Applies to
  • Microsoft Windows XP Home Edition
  • Microsoft Windows XP Professional
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