What is the Windows XP equivalent of 'User Choice' in the registry?

Question

What would be the Windows XP equivalent of deleting the key User Choice in the Windows 7/Vista registry (to restore the default program to be used to open a particular file extension)?

Answer 1

Never mind — I figured it out. In case anyone else needs this answer here is what works:

In XP I deleted one key up from where 'user choice' would be in Vista/Win 7.

So to restore the default program to open this extension, I deleted

HKEY_CURENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Fileexts\.myExt

(where .myExt is the extension you're trying to fix)