The installed version of MOUNTMGR.SYS is incompatible with Exchange Server

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at]  

Topic Last Modified: 2006-06-06

Microsoft® Exchange Server 2007 setup cannot continue because the installed version of Mountmgr.sys is incompatible with Microsoft Exchange.

Exchange 2007 setup requires that the cluster node have the update referred to by Microsoft Knowledge Base article 898790 installed.

The version of Mountmgr.sys currently installed on the cluster node may cause volume mount point failures. This problem occurs because of a problem in the Mountmgr.sys driver. This is an intermittent timing problem that can occur when a volume arrives to be mounted to a mount point.

To resolve this issue, install the update referred to by Microsoft Knowledge Base article 898790 (, and then rerun Exchange 2007 setup.

For more information about this issue, see Microsoft Knowledge Base article 898790, "Volume mount points on disks in a server cluster may intermittently become unavailable after you install Windows Server 2003 Service Pack 1" (