To configure a Microsoft Visual Studio Installer project to generate only MSI files instead of a setup.exe file, you can modify the project settings as follows:
Open your Visual Studio Installer project in Visual Studio.
In the Solution Explorer, right-click on your installer project and select "Properties" from the context menu.
In the Project Designer window, navigate to the "Output" tab.
Under the "Output type" section, select the "Windows Installer Package (*.msi)" option.
Ensure that the "Create setup program to install prerequisite components" checkbox is unchecked. This step is important because the setup.exe file is typically used to install prerequisite components, and we want to exclude it from the output.
Save the changes to the project properties.