>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?

The "official" approach is:

HKEY_CURRENT_USER\SOFTWARE\Vendor Company Name\App Name\Version Number\

For example:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\Visual FoxPro\6.0\

That's the way MS documents it in their windows architecture documentation.