We're happy to announce the release of the English version of an update to the Exchange Server 2007 SP1 Setup prerequisite check file. This update will allow you to install Exchange 2007 SP1 in a single-label domain (SLD). To read more history behind this, please go here.
Localized versions of this file will be available soon, and we'll update this blog post when they are available. Do not use the English version of the file if you are running a non-English version of Exchange 2007.