For those people that don’t study the Enterprise Vault Compatibility Guide :
One of the changes added to the Guide dated 24th June 2011 is support for Windows 7 Service Pack 1 in both it’s 32 bit and 64 bit variants.
You will need :
* Enterprise Vault 9 (any release), or
* Enterprise Vault 8 Service Pack 3 or later
Be aware of the caveats described in the following technote, linked from the Guide: