Announced at the beginning of this month, Windows Installer 4.5 Beta 2 went live on Microsoft Connect as of March 21. According to the Redmond company, Windows Installer 4.5 Beta 2 is designed to bring to the table down-level packages tailored on Windows XP SP2 and SP3, as well as Windows Vista RTM and SP1, and Windows 2003 Server SP1 and above. Microsoft has also managed to address a consistent list of issues that were identified in the previous version of the Windows Installer. It is important to note that Beta 2 is the last step preceding the finalization of Windows Installer 4.5.

"I am pleased to announce that Windows Installer 4.5 Beta 2 is now available from the Microsoft Connect site. If you have not signed up for the beta yet, please do - we are listed as 'Windows Installer 4.5' under the 'Available Connections' section of the site. If you have already joined the beta, please head back to the Connect site and download the updated bits, tools and documentation. This is our last planned beta release before we ship, so your feedback at this stage is especially important," stated Tyler Robinson, Program Manager - Windows Installer Team.

One aspect that you will need to be on the lookout for is the way Windows Installer 4.5 Beta 2 integrates with Vista SP1 and XP SP3. In this regard, Microsoft warned that deploying a pre-release version of Vista SP1 and XP SP3 on top of Vista RTM or XP SP2, with Windows Installer 4.5 already installed, can cause the Windows Installer registration to be broken. A workaround to such a scenario involves a simple Windows Installer 4.5 reinstall.

"Windows Installer v4.5 (MSI 4.5) is an update to Windows Installer 4.0 released in November 2006. Windows Installer 4.5 contains new and enhanced functionality and addresses some issues found in the Windows Installer 4.0 release. The goals of the Windows Installer 4.5 Beta 2 program are (1) to solicit feedback on new and enhanced features, (2) allow developers to evaluate and begin to plan for features available in the final release of MSI 4.5, and (3) augment the regression and application compatibility testing for Windows Installer based applications," reads an excerpt from the Windows Installer 4.5 Beta 2 documentation.

Microsoft Windows Installer 4.5.6001.22133 Beta is available for download here.