As stated, he is trying to install on 2007 SP2, this was only introduce in 2007SP3 [Ref 703039, E1096055]
Exchange System Manager is no longer a prerequisite on Enterprise Vault server
In Enterprise Vault 7.0 original release, SP1, and SP2, Microsoft Exchange System Manager (ESM) was a prerequisite for installation of the Enterprise Vault server software.
In Enterprise Vault 7.0 SP3, it is possible to run an Exchange mailbox archiving task or Journaling task without installing ESM on the Enterprise Vault server. The Enterprise Vault 7.0 SP3 server installation procedure does not display a warning if ESM, or the correct version of ESM, is not detected.
Notes:
- The ability to synchronize inherited permissions from the Exchange server to users' archives requires ESM to be installed on the Enterprise Vault server. Now that ESM is not a prerequisite, note the following:
* If ESM is installed on an Enterprise Vault server running 32-bit Windows Server 2003, you can still synchronize inherited permissions from the Exchange server to users' archives.
* Windows Server 2003 x64 SP2 prevents Exchange Server 2003 ESM from installing, so you cannot synchronize inherited permissions if the Enterprise Vault server uses this operating system.
- Enterprise Vault 7.0 SP3 still includes the ability to synchronize delegate permissions; that is, permissions set through Active Directory users and computers, or through Outlook folder permissions.