Microsoft KB Archive/940145

= The performance of a computer that is running Windows Vista may decrease as you run an application that calls the StretchBlt function =

Article ID: 940145

Article Last Modified on 9/11/2007

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APPLIES TO


 * Windows Vista Home Premium
 * Windows Vista Ultimate
 * Windows Vista Business
 * Windows Vista Enterprise
 * Windows Vista Home Premium 64-bit Edition
 * Windows Vista Ultimate 64-bit Edition
 * Windows Vista Business 64-bit Edition
 * Windows Vista Enterprise 64-bit Edition

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SYMPTOMS
The performance of a computer that is running Windows Vista may gradually decrease as you continually run an application that calls the StretchBlt function. Eventually, Windows Vista may stop responding.

When you use Windows Task Manager to monitor performance, you may notice that physical memory usage increases quickly.

Note When you close the application, Windows Vista releases the memory that the application uses. Therefore, system performance recovers.



CAUSE
When the application calls the StretchBlt function, Windows Vista allocates resources for this call. However, when the call is completed, Windows Vista does not release the resources. However, when the application calls the StretchBlt function again, Windows Vista allocates new resources for the call. Therefore, this problem occurs if the application calls the StretchBlt function many times.



Hotfix information
A supported hotfix is now 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 service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or 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. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Prerequisites
No prerequisites are required.

Restart requirement
After you apply this hotfix, you have to restart the computer to load the Win32k.sys file.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

Registry information
You do not have to make any changes to the registry.

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 Vista, 64-bit versions


STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
The StretchBlt function copies a bitmap from a source rectangle to a destination rectangle. If the dimensions of the destination rectangle do not fit the dimensions of the source rectangle, the StretchBlt function modifies the bitmap to fit the dimensions of the destination rectangle.

For more information about the StretchBlt function, visit the following Microsoft Web site:

http://msdn2.microsoft.com/en-us/library/ms532355.aspx

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

824684Description of the standard terminology that is used to describe Microsoft software updates

Keywords: kbfix kbqfe kbpubtypekc kbexpertiseadvanced kbexpertisebeginner kbhotfixserver KB940145

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