A program that throws many exceptions may run significantly more slowly on a computer that is running Windows Server 2003 with Service Pack 1

A program that throws many exceptions may run significantly more slowly on a computer that is running Microsoft Windows Server 2003 with Service Pack 1 (SP1).

This problem occurs because of the Data Execution Prevention (DEP) feature of Windows Server 2003. An option in Windows Server 2003 disables the DEP checks to improve program performance. However, if you use this option, it does not disable all the new exception-handling security checks that DEP performs.

Service pack information

To resolve this problem, obtain the latest service pack for Windows Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

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.After you apply this hotfix, the exception-handling security checks are disabled when DEP is disabled.

Prerequisites

You must have Windows Server 2003 SP1 installed to apply this hotfix.

Restart requirement

You must restart your 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.
Note This hotfix only enables the ability to disable the exception-handling security check by DEP. You must still add the program to the DEP exclusion list. To add the program to the DEP exclusion list, follow these steps:

1. Click Start, click Run, type sysdm.cpl, and then click OK.
2. On the System Properties dialog box, click the Advanced tab.
3. Under Performance, click Settings.
4. Click the Data Execution Prevention tab.
5. Click Turn on DEP on programs and services except those I select, click Add, and then add the program.

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section. This problem was first corrected in Microsoft Windows Server 2003 Service Pack 2.

Generally, exception handling takes less than 10 milliseconds. Therefore, a program that throws few exceptions does not run significantly more slowly. However, a large program that throws thousands of exceptions in a short time may run much more slowly.

To determine whether a program throws enough exceptions to affect performance, you can use a profiling utility or a debugging utility. Such utilities include the following:

• Dependency Walker
• Microsoft Visual Studio
• Microsoft Debugging Tools for Windows

For more information about the DEP feature, click the following article number to view the article in the Microsoft Knowledge Base: For more information about a similar problem in Windows XP, click the following article number to view the article in the Microsoft Knowledge Base: For more information about the terms that are used in this article, click the following article number to view the article in the Microsoft Knowledge Base: The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, regarding the performance or reliability of these products.