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Performance Issues When Loading Winmm.dll

This article was previously published under Q266327
This article has been archived. It is offered "as is" and will no longer be updated.
IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:
256986 Description of the Microsoft Windows Registry
When your Windows 2000-based computer loads the Winmm.dll file into memory, you may experience a delay. This delay may occur at different times, depending on how the Winmm.dll file is loaded.

Import Library

If a program loads the Winmm.dll file by using an import library, Winmm.dll is loaded when the program starts. In this case, you may experience a delay when you start the program.

NOTE: Performance can be significantly affected if the program is started many times by using a batch file.


If a program loads the Winmm.dll file by using LoadLibrary, Winmm.dll is loaded only when the program needs to used it. For example, if Explorer.exe plays a sound when you open a menu, the Winmm.dll file is loaded when the sound is played the first time. In this case, you may experience the delay when the the program loads the Winmm.dll file.
This problem occurs because the Winmm.dll file is trying to load the AUX library, which does not exist.
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To resolve this problem, obtain and install Service Pack 1 (SP1) for Windows 2000, and then use Registry Editor (Regedt32.exe) to view the following registry key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32
Add the following registry value:
Value Name: aux
Value Type: REG_SZ
Data: mmdrv.dll
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.
The Winmm.dll file is a 32-bit library that supports multimedia services; it is used to initialize .wave, .midi, and .aux files. Note that .wave and .midi devices are mapped to the Wdmaud.drv file in the Drivers32 registry key, but AUX is not, causing Winmm.dll not to succeed when it tries to load the AUX library.

Article ID: 266327 - Last Review: 12/05/2015 20:47:54 - Revision: 3.2

Microsoft Windows 2000 Server, Microsoft Windows 2000 Advanced Server, Microsoft Windows 2000 Professional Edition

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