OK, that's good, I think...

The problem comes from not being able to run programs in a 16-bit Virtual Machine.
And there seems to be several reasons why it can happen.

Here are two tests recommended by Microsoft ...

Open the run command line (Start | Run) or WinLogo+R.
Enter the command sysedit.

If it does not start the system configuration utility ... it may still be an NTVDM error.

If it does start, try to open edit.com from the Run command line.

If it can not open the editor, it may be a Windows on Windows problem.<hr>
In my case, when I took those images, I had a problem with one of my video cards, and the driver was causing problems.

After replacing the video card and installing the new driver, the problem magically disappeared. But there can be many causes.

I had 2.50 at the time, but it's a Windows/MCS problem, not a PBP problem.
You can still compile from the command line or with a batch file.
(As long as there isn't an associated .pif file).
<br>