The original WASP IV was a 16-bit DOS application. With the phasing out of 16-bit subsystems in 64-bit Windows (starting from Windows 7, 8, 10, and 11), running the original becomes challenging. This is where the search for a "64-bit free" version comes into play.
The most critical piece of information for a prospective user is this:
If you need a free, modern, 64-bit gas turbine performance simulation tool, consider: