>How do you determine which files you need to distribute and where they are supposed to go? Is this trial and error?

You mean the runtime files? There is a sample ISExpress file for VFP6 here and a FAQ on what files you need. But I forgot how I came up with that list, I think MS has a KB on their site, and looking at what the Setup Wizard automatically adds, I found something that works.

Most everything goes to teh System directory.