When right-clicking a file you may see an option called Open-With, which lists few number of programs on you computer to open the file with. To clear this list, or to remove the unwanted applications from the list (for the said file-type), follow these steps.

> Click Start, Run, Type REGEDIT

> Navigate to the following key:

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

> Find the extension you wish to edit and click on the "+" sign to expand OpenWithList

( In the right pane, you will see a list with the programs, like "paint.exe", "notepad.exe" etc )

> Use the File, Export option to backup the key.

> Click on the one you wish to delete and press the delete button


Still some items may show up in the Openwith lists, which comes from the HKEY_CLASSES_ROOT registry key, which is common for all the user profiles. You may remove the entries from the following key:

HKEY_CLASSES_ROOT\ .nnn \ OpenWithList

Where nnn is a file extension. With that removed, Windows may still show some default Open-With lists. Depending upon the file type, the open-with listing is generated from the subkeys under:

HKEY_CLASSES_ROOT \ SystemFileAssociations \ <Type>\

Simply put, don't remove this part as it affects many file types, not a particular one.