|Immediate Custom Actions|
Immediate custom actions are the opposite of deferred ones and can be scheduled at any time.
All immediate custom actions that fall between "InstallInitialize" and "InstallFinalize" are executed before deferred ones.
As these actions don't have commit and Rollback support they shouldn't change machine state.
An immediate custom action can change the MSI database to dynamically alter its "settings", see "Dynamically Update Dialog Controls" for an example.