To develop and run the program, you will need to install the Visual Basic 6.0 IDE, which is no longer supported on any version of Windows that is still supported by Microsoft.
To run the unit tests, you will also need to install SimplyVBUnit on your machine.
With the Visual Basic 6.0 IDE open, go to Tools, then Options, and in the General tab, within the Error Trapping frame, make sure the setting is set to "Break on Unhandled Errors".