The SourceDir property is the root directory that contains the source cabinet file or the source file tree of the installation package. This value is used for directory resolution.
The directory that contains the installation package.
The ResolveSource action must be called before using the SourceDir property in any expression or attempting to retrieve the value of SourceDir with MsiGetProperty. The ResolveSource action should not be run while the source is unavailable, such as when uninstalling an application, because this can cause an unintended prompt for the source media.
||Windows Installer 5.0 on Windows Server 2012, Windows 8, Windows Server 2008 R2 or Windows 7. Windows Installer 4.0 or Windows Installer 4.5 on Windows Server 2008 or Windows Vista. Windows Installer on Windows Server 2003 or Windows XP. See the Windows Installer Run-Time Requirements for information about the minimum Windows service pack that is required by a Windows Installer version.