Applying Small Updates by Patching the Local Installation of the Product
A small update can be applied to an application by patching the local installation of the application.
To apply a small update patch to a local installation of the product
- Launch the installation of the patch from the command line or by using an executable. To launch from the command line, use msiexec /p patch.msp REINSTALL=[Feature list] REINSTALLMODE=omus. To launch from an executable, call MsiApplyPatch or the ApplyPatch Method and provide the same command line arguments.
- When patching a client installation, the installer ignores the installation source and proceeds to patch the files that are already installed on the user's computer.
- The installer changes any patched components marked as run-from-source to run-locally. Users are unable to run these components from the source as long as the patch remains on the computer.
- The installer adds any transforms used to update the .msi file or adds patch-specific information to the user's profile.
- The installer caches the .msi file on the user's computer so that it can perform installation-on-demand, reinstall, and repair of the application. After a patch is applied to a standalone installation, the installer references two or more source lists to external files: one for the original source and one for each patch that has been applied.