Background:

Installing Exchange 2007 SP1 gives an error on the Mailbox Role.

Error:

Unable to remove product with code 6574fdc2-40fc-405a-9554-22d1ce15686b.  Unable to remove product with code 6574fdc2-40fc-405a-9554-22d1ce15686b. Fatal error during installation. Error code is 1603.
Fatal error during installation

Solution:

1. Stop the "Microsoft Exchange Search Indexer" service and the "Microsoft Exchange Transport Log Search" service.
2. Remove the Microsoft Full Text Indexing Engine for Exchange using msiexec.exe /X {6574fdc2-40fc-405a-9554-22d1ce15686b}
3. Refer to http://consumer.installshield.com/kb.asp?id=Q111019 for additional causes.