Installation sequence restrictions for multi-package transactionshttp://blogs.msdn.com/heaths/archive/2009/07/03/installation-sequence-restrictions-for-multi-package-transactions.aspxWindows Installer 4.5 introduced a feature to install multiple packages in a single transaction. Multi-package transactions allow setup developers to install multiple packages as an atomic unit that are installed together, or rolled back completely. Youen-USCommunityServer 2.1 SP1 (Build: 61025.2)