I get asked this every once in a while and since I couldn't find it mentioned anywhere I thought it might be a good idea to post it here. Under certain circumstances it may be necessary to install the OpsMgr 32-bit agent on a 64-bit operating system to monitor a 32-bit application. This is a supported configuration but the 32-bit agent must be installed manually and both the 32-bit and 64-bit OpsMgr agent cannot be installed simultaneously.
It may also be necessary to install the OpsMgr 32-bit agent on a supported 64-bit operating system for management pack monitoring of some 32-bit applications together with some 64-bit applications which do not support 64-bit agent monitoring via their management pack. One such application is System Center Configuration Manager 2007. See the System Center Configuration Manager 2007 management pack release notes for Operations Manager 2007.
To install the 32-bit OpsMgr agent on a supported 64-bit operating system the agent must be installed manually. This can be accomplished by running the MOMAgent.msi from the agent\i386 folder of the OpsMgr installation media, either manually or through automated command line (see the OpsMgr deployment guide for further information). Prerequisites for the agent installation must be met prior to installing the agent. These include Microsoft XML 6.0 (msxml\i386 on the distribution media) and the Active Directory Management pack Helper Object (oomads.msi from the helperobjects\i386 folder on the distribution media required for Domain Controllers only).
Once the 32-bit agent is installed manually please note that any agent hotfixes which may be required in the future must be installed manually on the agent.
Multi-homing the 32-bit agent on a 64-bit supported operating system is currently not supported.
The 32-bit operations manager agent is supported on the same operating systems as are supported by the 64-bit operations manager agent. Please see the supported configurations guide for more information.
J.C. Hornbeck | Manageability Knowledge Engineer