I'm finding that if there's no entry for the .hlp in that key, then the app can't find the .hlp, despite the fact that it's in the same directory as the executable. The app is an MFC app that simply calls WinHelp. It also contains code that sets the help file path to the same directory as the one where the .EXE lives.
Once the registry entry's there, the app has no problem opening up help but until it's there, the app can't find the .hlp but rather the Windows help engine offers to allow the user to browse to find it. Anybody have any more information?