I do not mess with the Registry, only until I do careful thoughts about what I want to do. After much thinking of your problem, I find the only solution is a REGEDIT.
then do CTRL + F,
then type openwith
Then you may find a list of file extention folders below that.
I could not give you the entire Registry location because mine my be different yours.
The idea is to Edit the SOL folder to give the "Open With..." notice again. Compare that folder with others, and Folder Options "File Types" tab....to determine what to Delete.
You may have to live with it.
Edit the Registry at your own risk.
Description of the Microsoft Windows Registry