Overlapping layered windows are not displayed in the correct order in Windows Server 2003 or in Windows XP

In Windows Server 2003 or in Windows XP, one or more applications create layered windows that have a WS_EX_LAYERED style. Additionally, the layered windows overlap one another. However, the overlapping layered windows are not displayed in the correct order. For example, an application creates a window and then creates a pop-up window inside the parent window. In this situation, the parent window unexpectedly covers an area of the pop-up window.

When this problem occurs, users cannot access the covered area.

This problem occurs because the Win32k.sys driver displays the order of layered windows incorrectly.

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.

Note This hotfix fixes some sources of this problem, but does not completely eliminate the symptoms. With the hotfix installed there will be fewer instances of the problem, but it still can occur.

Prerequisites

To apply this hotfix, you must have Windows Server 2003 Service Pack 1, Windows Server 2003 Service Pack 2, Windows XP Service Pack 2, or Windows XP Service Pack 3 installed.

For more information, click the following article number to view the article in the Microsoft Knowledge Base: For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

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 2003 with Service Pack 1, x86-based versions

Windows Server 2003 with Service Pack 2, x86-based versions

Windows Server 2003 with Service Pack 1, Itanium-based versions

Windows Server 2003 with Service Pack 2, Itanium-based versions

Windows Server 2003, x64-based versions

Windows Server 2003 with Service Pack 2, x64-based versions

Windows XP with Service Pack 2

Windows XP with Service Pack 3

To work around this problem, use one or more of the following methods:

• Do not use layered windows. If you want to use layered windows to create irregular-shaped windows, use window regions instead of layered windows.
• Do not change display configurations when the applications are running. The problem that is described in the "Symptoms" section frequently occurs when users change their display configurations. For example, do not extend the desktop for dual monitors.
• Restart all the applications that have overlapping layered windows.

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

You can use a layered window for the following reasons:

• To improve performance and visual effects for a window that has a complex shape
• To animate window shapes
• To use alpha-blending effects

The system automatically composes and redraws layered windows and the windows of underlying applications. For more information, visit the following Microsoft Web site:For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base: