I installed InstallShield 12 Express and defined some Custom Dialogs. At the 'Setup Complete Success' dialog I added the checkbox asking whether to lunch the program at the end of setup. With first installation this works fine. But than I am trying to run the setup once again, I receive another set of dialog (one of them asks me if I want modify, repair or remove my application). Where can I customize those dialogs?
You can edit the text on that dialog in the Text and Messages view. The dialog itself is not one that is available for further customization in the Express edition of InstallShield.
The Premier and Professional editions include a dialog editor that let you modify the text and layout of any dialog, as well as add custom dialogs.
