Today was released a new kb which explain why Exchange Server 2007, Forefront Security for Exchange Server and Sharepoint 3.0 can be affected after a installation of the Windows Server 2003 SP2, and of course how to fix it.
After you install Microsoft Windows Server 2003 Service Pack 2 (SP2) on a server, the following services do not start:
|•||Microsoft Exchange Information Store service|
|•||Microsoft Exchange Transport service|
Additionally, you may receive the following error message when you start the server:
Error 1068: The dependency service or group failed to start
Read more at source: http://support.microsoft.com/default.aspx?scid=kb;en-us;936541&sd=rss&spid=10926