This article lists known issues with Microsoft Operations Manager (MOM) 2005 agents that interoperate in 64-bit and 32-bit environments. The article discusses the following scenarios:

• A 32-bit MOM agent interoperates with a 64-bit operating system or with a 64-bit application.
• A 64-bit MOM agent interoperates with a 32-bit application.
• A 64-bit MOM agent interoperates with a 64-bit operating system or with a 64-bit application.

Scenario 1: A 32-bit MOM agent interoperates with a 64-bit operating system or with a 64-bit application

The following issues may exist in this scenario:

• Performance counters
  
  A 32-bit MOM agent cannot interoperate with a 64-bit performance counter. Therefore, a 64-bit operating system or a 64-bit application must ship 32-bit versions of their performance counters to support 32-bit and 64-bit interoperability.
  
  If a 64-bit operating system or application does not include 32-bit versions of their performance counters, MOM performance rules that try to call the performance counter cannot collect the relevant data. In this case, MOM generates the following alert:
  
  Performance Provider - Performance counter does not exist.
• Binaries
  
  A 32-bit MOM agent can run a 64-bit executable application and capture any standard output that the application returns. For example, the agent can capture tasks or command-line responses. In 64-bit operating systems, there are 64-bit and 32-bit versions of the System32 folder and the Program Files folder. These folders are designed to separate the 32-bit and 64-bit binaries. The 64-bit versions of these folders are named System32 and Program Files. The equivalent 32-bit folders are named Syswow64 and Program Files (x86). This design enables 32-bit applications to successfully run on 64-bit operating systems.
  
  To interoperate with 32-bit applications, Windows components and applications that install 64-bit binaries in the System32 and Program Files folders must install equivalent 32-bit binaries in the Syswow64 and Program (x86) folders. Windows will redirect 64-bit and 32-bit applications that try to use these binaries to the appropriate folder.
  
  If the 64-bit component or application does not install both the 64-bit binaries and the 32-bit binaries, the MOM agent may experience Task Status events, script errors, or response failures that indicate that a file could not be found.
• Registry
  
  64-bit operating systems contain 32-bit and 64-bit versions of the registry. 64-bit applications write their registry keys to the 64-bit registry. 32-bit applications write their registry keys to the 32-bit registry. By default, when a 32-bit application makes a registry call, Windows will direct the application to the 32-bit registry. A 32-bit application cannot access registry keys that are written by 64-bit applications to the 64-bit registry.
  
  Many 64-bit Windows components write registry keys that appear in both registries. This behavior occurs for compatibility reasons. Many 32-bit applications use the registry to obtain information about the operating system. Therefore, a management pack that does not consider 64-bit Windows registry behavior may have issues with Computer Attribute discovery, with Computer Group population, or with the corresponding management routines.
• Event log
  
  The Windows event log relies on message files to acquire event message text. These message files are frequently located in the installation directory of the Windows component or application. Therefore, these message files may be installed in the System32 and Program Files folders or in the Syswow64 and Program Files (x86) folders. 64-bit Windows components and applications that install their messages files in these folders must also install corresponding 32-bit versions of the message files in the appropriate subfolders under the Syswow64 and Program Files (x86) folders.
  
  Note This requirement effects only applications that try to install files in the System32 or Program Files folders.
  
  When Windows components and applications do not ship both versions of the message files, the 32-bit MOM agent cannot access their event log messages. When this issue occurs, an event that looks similar to the following may be displayed in the description of an alert:
  
  Unable to expand message 301 [301].
  
  Rules that use an event description as a criteria cannot function because of this issue.

Scenario 2: A 64-bit MOM agent interoperates with a 32-bit application

The following issues may exist in this scenario:

• Performance counters
  
  A 64-bit MOM agent cannot use a performance counter from a 32-bit application. Therefore, a 64-bit MOM agent cannot manage performance counters from 32-bit applications.
• Registry
  
  64-bit operating systems contain 32-bit and 64-bit versions of the registry. 64-bit applications write their registry keys to the 64-bit registry. 32-bit applications write their registry keys to the 32-bit registry. By default, when a 32-bit application makes a registry call, Windows will direct the application to the 32-bit registry. A 64-bit application cannot access registry keys that are written by 32-bit applications to the 32-bit registry.
  
  Therefore, a management pack that does not consider 64-bit Windows registry behavior may have issues with Computer Attribute discovery, with Computer Group population, or with the corresponding management routines.

Scenario 3: A 64-bit MOM agent interoperates with a 64-bit operating system or with a 64-bit application

No known issues exist for a 64-bit MOM agent (IA-64) that manages a 64-bit operating system or application.