Controlling who can run an executable

[Svennglenn]

> What I want:
> - the simplest thing that could possibly work!
>

Have the program check for a file hidden somewhere on the computer.
For instance, if the file dummyfile.dll doesn't exist in the
windows/system32 folder the program just doesn't start. And when you
install the program on her computer just add this file. And if anyone
copies the program the can't run it on any other computer because they
doesn't know the name of the file that's needed to start the program.

How about that?