Concurrent Installations: Significance and Directions

Concurrent Installations, also called Nested Installations, install another Windows Installer package during a currently running installation.

The use of concurrent installations is not a good practice because they are difficult for customers to service. Patching and upgrading may not work with concurrent installations. The recommended alternative to using concurrent installations is to instead use a setup application and external UI handler to install several Windows Installer packages sequentially.

Concurrent installations are sometimes used in controlled corporate environments to install applications that are not intended for the public.

Follow these guidelines if you decide to use concurrent installations.

• Do not use concurrent installations to install or update a shipping product.
• Concurrent installations should not share components.
• An administrative installation should not contain a concurrent installation.
• Integrated Progress Bars should not be used with concurrent installations.
• Resources that are to be advertised should not be installed by a concurrent installation.
• A package that performs a concurrent installation of an application should also uninstall the concurrent application when the parent product is uninstalled. A nested installation exists under the context of the parent product in the Add/Remove Programs in Control Panel.