MSI 4.5 Released

Today TechEd North America started, and many companies use TechEd to announce new products and releases. So here's the first announcement that caught my attention:

Windows Installer 4.5 has been released

Version 4.5 of the MSI engine brings new features such as

Multi-Package Transactions that enable developers to seamlessly chain multiple Windows Installer packages
Embedded Custom UI, so a setup.exe launcher is no longer required as had been the case with the "external UI" functionality
Patch Uninstall Custom Actions

and several other enhancements.

While MSI 4.0 was only available for (and as part of) Windows Vista, the MSI 4.5 runtime can be redistributed to Windows XP SP2, Windows Server 2003 SP1, or above.

More information:

Windows Installer 4.5 is now available! (Windows Installer Team Blog)
What's New in Windows Installer 4.5 (MSDN documentation)
Windows Installer 4.5 SDK
Windows Installer 4.5 Redistributable
Windows Installer 4.5 is available (Microsoft Knowledge Base article 942288)

Stefan Krueger