On a computer that is running Windows Server 2008 for Itanium-based Systems and that supports Dynamic Hardware Partitioning (DHP) features, you can hot add or hot replace processors. When you do this, you may receive a Stop error message that resembles the following message: Notes

• You can add or replace a processor to a computer while the computer is running, and the operating system automatically recognizes the change.
• The parameters in the Stop error message vary, depending on the configuration of the computer.
• Not all "0x000000D1" Stop errors are caused by this problem.

The issue occurs because a processor device startup function in ACPI driver is acquiring a spin lock, but the function is built as pageable code.

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.

Prerequisites

This hotfix requires Windows Vista or Windows Server 2008 for Itanium-based Systems to be installed on the computer.

Restart requirement

You have to 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.

Windows Server 2008, Itanium-based version

For information about DHP, visit the following Microsoft Web sites. These site swill help you understand the problem.

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