Based on the original .NET 3.5 module, as published by Indigo Rose, here are new modules for the current .NET Framework 4.0.
There are two detection modules in this package:
.NET 4.0 Include - assumes that you include the .NET 4.0 full package installer (dotNetFx40_Full_x86_x64.exe) in your bootstrapper, which will add 48.1 MB to your setup.
You can download the installer from here: http://www.microsoft.com/downloads/details.aspx?familyid=0A391ABD-25C1-4FC0-919F-B21F31AB88B7
.NET 4.0 Download - assumes that you download the web installer (dotNetFx40_Full_setup.exe) and that you place it on your own web server. At runtime, the bootstrapper will first download the web installer from your server, which will then download the required files for the detected platform from Microsoft and finally start the installation. This all can be done passively, so no user interaction is required.
You can download the web installer from here: http://www.microsoft.com/downloads/details.aspx?FamilyID=9cfb2d51-5ff4-4491-b0e5-b386f32c0992
Installation
Download this file: http://www.mindquake.com.br/files/msi/NET4Framework.zip
Decompress the zip file in the "Bootstrap\Dependencies" sub folder of your MSI Factory installation. When you restart the Bootstrapper Designer, the two new modules will be available.
This dependency module is not officially supported by Indigo Rose. Use it at your own risk, and feel free to modify it to fit your needs better. Feedback is always welcome.