A) Synchronous: Windows Installer runs the custom action SYNCHRONOUSLY to the main installation. It WAITS for the custom action to complete successfully before continuing the main installation.

b) 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.

c) A synch, 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.

d) A synch, no wait: Windows Installer runs the custom action simultaneously with the main installation. It doesn’t wait for completion of the custom action and doesn’t check the exit code ALSO.

A) Synchronous: Windows Installer runs the custom action synchronously to the main installation. It waits for the custom action to complete successfully before continuing the main installation.

b) 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.

c) A synch, 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.

d) A synch, no wait: Windows Installer runs the custom action simultaneously with the main installation. It doesn’t wait for completion of the custom action and doesn’t check the exit code also.