Article ID: 975741 - View products that this article applies to.
On a computer that is running Windows 7, some function keys and keyboard shortcuts do not work correctly. Every time that you press a function key or keyboard shortcut, the corresponding function is triggered two times.
For example, assume that your computer keyboard has a built-in Calc key that lets you start Calculator. When you press the Calc key, two instances of Calculator start. Or, assume that you have a Mute key on the keyboard. When you press the Mute key or the Fn+F6 keyboard shortcut to mute or unmute the system sound, the sound is not muted or unmuted.
This problem is a timing related issue. Therefore, the chances of the problem occurring can be influenced by different factors. Observed examples that increased the chances of the problem occurring include the following:
This problem occurs because of an error in certain hook logic in Windows Explorer of Windows 7. This error causes Windows 7 to send two commands every time that you press a function key or keyboard shortcut. In the mute example that is described in the “Symptoms” section, Windows 7 sends two commands to the sound mixer for each mute or unmute request. Therefore, for the mute and unmute operations, the second command undoes the operation of the first command. This behavior makes it appear that the mute or unmute function does not work.
Hotfix informationA 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:
PrerequisitesNo prerequisites are required.
Restart requirementYou must restart the computer after you apply this hotfix.
Hotfix replacement informationThis hotfix does not replace any other hotfixes.
File informationThe Global 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 7 file information notesImportant Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.
Windows 7, x86-based versions
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Windows 7, x64-based versions
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Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about software update terminology, click the following article number to view the article in the Microsoft Knowledge Base:
(http://support.microsoft.com/kb/824684/LN/ )Description of the standard terminology that is used to describe Microsoft software updates
Article ID: 975741 - Last Review: October 11, 2011 - Revision: 3.0
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