In Visual Studio 2010, you can use the ClickOnce and Windows Installer deployment technologies to deploy Office solutions that target both Microsoft Office 2007 and Microsoft Office 2010. The main advantage of using Windows Installer to deploy your Office solutions is to install application-level add-ins to AllUsers, rather than the current user only.
There are detailed steps for creating a Windows Installer (.msi) file for Office 2007 and Office 2010 solutions at http://msdn.microsoft.com/en-us/vsto/ff937654.aspx and code samples at http://code.msdn.microsoft.com/VSTO2010MSI.
For information about the registry keys for deploying to AllUsers, see http://msdn.microsoft.com/en-us/library/bb386106.aspx.
For developers using Windows Installer XML, there is some useful information at http://stackoverflow.com/questions/532447/how-do-you-use-wix-to-deploy-vsto-3-0-addins. The steps are similar for Office solutions in Visual Studio 2010.
If you have any questions about the steps, search for answers or post questions in the Visual Studio Tools for Office forum at http://social.msdn.microsoft.com/Forums/en-US/vsto/threads.
Mary Lee, Programming Writer.
Saurabh Bhatia, Program Manager.