>What rules need to be followed when creating and saving registry entries?
>
>Does anyone know of a good information source on Windows registry?
>
>I would like to create a unique id on each users machine whenever my app runs for the first time. I was thinking that I would make an entry under hkey_local_machine\software\myapp. Is that the right approach?

There is a registry class that you can use. There are a couple of articles written by Colin Nichols on MSDN on accessing the registry from VFP.