- Synchronous
- Synchronous, ignore exit code
Windows Installer runs the custom action synchronously to the main installation. It waits for the custom action to complete before continuing the main installation; the action can be either success or fail.
- Asynch, wait at end of sequence
Windows Installer runs the custom action simultaneously with the main installation. At the end it waits for the exit code from the custom action before continuing.
- Asynch, no wait