When you try to install Exchange Server 2007 Service Pack 1 or Microsoft Exchange Server 2007 SP2 on an Exchange Server 2007-based computer, Setup fails

When you try to install Microsoft Exchange Server 2007 Service Pack 1 (SP1) or Microsoft Exchange Server 2007 Service Pack 1 (SP2) on a Microsoft Exchange Server 2007-based computer, Setup fails. Additionally, you receive the following error message:

To resolve this problem, run Setup again from the command line in the installation mode and install the same roles that you were previously installing. For example, if you were installing the Hub Transport role that you would resume Setup with this command: Note The Setup program has to complete the role(s) installation in which it failed before you can install other roles.

During the initial installation, Setup puts watermarks into the registry. Therefore, the Setup program resumes from where it left off if installation fails.

For more information about how to install Exchange Server 2007 from the command line, visit the following Microsoft Web site:
http://technet.microsoft.com/en-us/library/aa997281(EXCHG.80).aspx

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.