A registry newbie. Here we go.
First things first.
Registry Backup as a safety net is always important.
http://beemerworld.com/tips/registrybackup.htm
There seems to be a few default editor's listed for Microsoft Frontpage.
My best guess would be that the default editor is located @:
HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer \Default HTML Editor
See if this jives with your machine.
Go see what the default HTML Editor is as I listed it above.
Change the Default HTML Editor in the Internet Properties/Programs tab and see what you read at the registry address I gave previously. See if it changed.
You'll at least know where the Default is located then.
The rest you will ahve to continue researching on your own. I couldn't find the alternate HTML Editors as I mentioned in my first post this time around.
Cheers!