Where does Windows store its “Open With” settings?

Question

I\'m trying to programmatically check file associations by the file extension (for example .jnlp files). I keep reading that

Answer 1

Take a look in:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\

and the sub-key of that is the extension you reassigned. Under that there will be the UserChoice and OpenWithList sub-keys which will contain your redefinition.

You may also want to read http://support.microsoft.com/kb/950505 which talks about your issue.