You may receive an "Unable to load MQQM.dll" error message when you try to install Message Queuing 2.0 (322156)

SYMPTOMS

When you try to install Microsoft Message Queuing (also known as MSMQ) 2.0 Client or Server, the installation may fail, and you may receive the following error message:

Error: Unable to Load MQQM.dll
Error Code: 0x7F

CAUSE

This problem may occur if Message Queuing was installed previously and then removed later. The uninstallation may not have removed all the MSMQ dynamic-link libraries (DLLs) successfully. When you try to reinstall Message Queuing, the Microsoft Windows File Protection Service may not permit the DLLs to be replaced by the DLLs from the installation CD.

RESOLUTION

To resolve this problem, follow these steps:

Manually remove Message Queuing.
Remove any Message Queuing hotfixes that have been installed.
Restart your computer.
Reinstall Message Queuing by using the original Windows 2000 installation CD as the source for the files.
Reapply the latest service pack for Windows 2000.

For additional information about how to manually remove Message Queuing, click the following article number to view the article in the Microsoft Knowledge Base:

298439 How to manually remove Microsoft Message Queue Server from Microsoft Windows 2000

Also, make sure that no Message Queuing hotfixes are still installed on the computer. Remove any Message Queuing hotfixes, and then restart the computer.