Change settings in Registry for file extentsion and mime/type
*Example for fictional MIME-type application/x-oxo and file ending .oxo:
[HKEY_CLASSES_ROOT\.oxo] @="oxo_file" [HKEY_CLASSES_ROOT\oxo_file] @="OXO Special" [HKEY_CLASSES_ROOT\oxo_file\shell] [HKEY_CLASSES_ROOT\oxo_file\shell\open] [HKEY_CLASSES_ROOT\oxo_file\shell\open\command] @="\"C:\\Oxo\\openprog.exe\" %1" [HKEY_CLASSES_ROOT\MIME\Database\Content Type\application/x-oxo] "Extension"=".oxo"