I thought I posted an answer to this before, and Tim Barrett’s tweet prompted me that I hadn’t (when i searched for it).
The answer to the problem Susan explains here is…
“I wanted to update this feedback, just to let you know how I fixed it and the cause.
I installed the UM role on this Exchange Server a while back whilst testing that feature for 3CX phone systems we sell. I believe that the Exchange Server was in a “mid state” of install of the UM role.
To fix, I downloaded the full blown Exchange 2007 with SP1 CD, and I created a folder in
c:program fileswindows small business serverbinCMPNENTS
C:Program FilesWindows Small Business ServerBinCMPNENTSEXCHSRVR80SetupServerRoles
I then copied into that folder the “UnifiedMessaging” folder of the Exchange CD I downloaded.
Then, I ran the Change installation for Exchange 2007 SP1 from Programs and Features, and clicked through that installer.
Lastly, I ran the SP2 installation tool and all was well.
Hope this is in someway helpful?”