Ron,
You're either very lucky, or all the systems that run your applications are fairly new. On "older" systems, a number of system support files may need to be added and/or updated or the VFP runtimes will act "flaky" or simply fail. Also, by not registering these components, it'll make the system "work" harder to fire up your application, and potentially allow another application to register their versions of these files, so your application won't use your files at all!
Copying files is not a substitute for using a good installer for your Windows applications.
Rick