A hotfix is available to enable CrashOnCtrlScroll support for a USB keyboard on a computer that is running Windows Vista SP1 or Windows Server 2008

Windows includes a feature that you can use to force a computer to restart if the computer has stopped responding. This feature generates a memory dump file (Memory.dmp). When you use this feature, you receive a Stop error message that resembles the following:

After you enable this manual crash feature, you can generate a memory dump file by first holding down the right CTRL key and then pressing the SCROLL LOCK key two times. This manual crash feature is available for PS/2 and for universal serial bus (USB) keyboards. PS/2 keyboards use the i8042prt.sys driver that is included with the keyboard.

However, this hotfix is necessary for the USB keyboard driver (Kbdhid.sys) in Windows Vista and in Windows Server 2008.

There is a limitation with the USB keyboard driver (Kbdhid.sys) that prevents you from generating a memory dump. The CTRL+SCROLL LOCK+SCROLL LOCK keyboard shortcut does not work if the computer stops responding at a high interrupt request level (IRQL). This limitation exists because the Kbdhid.sys driver operates at a lower IRQL than the i8042prt.sys driver.

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 the problem described in this article. 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.

Important Windows Vista and Windows Server 2008 hotfixes are included in the same packages. However, only one of these products may be listed on the �Hotfix Request� page. To request the hotfix package that applies to both Windows Vista and Windows Server 2008, just select the product that is listed on the page.

Prerequisites

To apply this hotfix on computers that are running Windows Vista, you must have Windows Vista Service Pack 1 (SP1) installed. For more information, click the following article number to view the article in the Microsoft Knowledge Base: No prerequisites are required for computers that are running Windows Server 2008.

Restart requirement

You must restart the computer after you apply this hotfix.

Hotfix replacement information

This hotfix does not replace a previously released hotfix.

Registry information

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.
After you apply this hotfix, you must make the following registry changes to resolve this problem:

1. Click Start, click Run, type regedit, and then press ENTER.
2. Locate and then click the following registry subkey:
   
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\kbdhid\Parameters
3. Click Edit, point to New, and then click DWORD Value .
4. Type CrashOnCtrlScroll, and then press ENTER.
5. Click Edit, and then click Modify.
6. Type 1, and then click OK.
7. Exit Registry Editor.

Note You must restart the computer for the changes that you made in the register settings to take effect.

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 and Windows Server 2008 file information notes

The .manifest files and the .mum files that are installed in each environment are listed separately in the "Additional file information for Windows Server 2008 and for Windows Vista" section. These files and their associated .cat (security catalog) files are critical to maintaining the state of the updated component. The .cat files are signed with a Microsoft digital signature. The attributes of these security files are not listed.

For all supported x86-based versions of Windows Server 2008 and of Windows Vista

For all supported x64-based versions of Windows Server 2008 and of Windows Vista

For all supported Itanium-based versions of Windows Server 2008

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 Windows Server 2008 Service Pack 2.

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

Additional file information for Windows Server 2008 and for Windows Vista

Additional files for all supported x86-based versions of Windows Server 2008 and of Windows Vista

Additional files for all supported x64-based versions of Windows Server 2008 and of Windows Vista

Additional files for all supported Itanium-based versions of Windows Server 2008