If I run winfile d: it starts Explorer?

A. If you try and pass WINFILE.EXE (the old File Manager pre 4.0) a drive, expecting it to start by default on that drive, you will find that it starts WINFILE as normal and then opens an Explorer view of the drive specified, e.g.

C:> winfile d:

would start a File Manager session and an Explorer session which points to d:

This behavior is not a bug and is caused by a misunderstanding of the parameters expected by WINFILE.EXE. Any parameters passed to WINFILE.EXE are interpreted that it should run as a program, e.g. you could type

C:> winfile notepad c:file.txt

and it would start a File Manager session and a notepad session editing file.txt.

The reason Explorer starts if you specify a drive letter is that under NT and 95/98 any directory listings are executed by Explorer. Try typing C: from Run and it will start Explorer pointing to C: