The Windows Installer SDK ships a library named patchwiz.dll. This contains the logic to build a patch from pairs of database packages (.msi files, or simply MSIs) along with other configuration properties. Another tool that the SDK ships is msimsp.exe which uses patchwiz.dll and parses command line options.
While we hope you’ll love Visual Studio 2010 for all the application development it enables with powerful features and a robust extension model that enables great extensions like the Productivity Power Tools, if you ever need to uninstall Visual Studio it can be difficult.
After installing the last several releases of Visual Studio, you’ll find shortcuts to command prompts that automatically set up the PATH, INCLUDE, LIB, and other environment variables. At least with Visual Studio 2010 these command prompts have larger buffers and enable quick edit mode,