If you open up any
Win32 application in a
Hex editor (or even a text editor such as notepad), you will see this in the first few lines. This is because it is coded into every
Win32 program to deal with the same application structure as
DOS. If there is no Windows environment present, it simply displays the message, and exits.
Try it:
Drag
notepad.exe onto
notepad. You should see it quite easily.