Customizing the Open With menu

    To add "MyProg.exe" to the OpenWith list of ".xyz" files, create a two

keys:

HKEY_CURRENT_USER\Software\Classes\Applications\MyProg.exe\shell\open\command

@="C:\Program Files\MyProg\MyProg.exe" "%1"

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.xyz\OpenWithList

x=MyProg.exe

MRUList=abc...x

    (where x is the next available letter).