http://msmvps.com/blogs/installsite/archive/2009/07/04/msi-compatibility-lying-about-versionnt-and-servicepacklevel.aspxMSI 5 on Windows 7 introduces a new application compatibility setting, as Chris Jackson describes in his blog . To work around too strict OS version checks in LaunchConditions, Windows Installer can automatically try several variations of values for theenCommunityServer 2008.5 SP2 (Build: 40407.4157)