HKEY_CLASSES_ROOT/batfile/shell
Right click on the Default entry, choose "Modify", and type Edit.Or:-
Go to HKEY_CLASSES_ROOT\batfile\shell\open, now change it to HKCR\batfile\shell\run.WARNING: DO NOT INCREASE THE LENGTH OF THE VALUE.
The final step is to go to the explorer and select File Types tab in 'option' Options in View menu and search MS-DOS Batch File then select Edit. Now as you can see, the three last buttons now are enabled and you can select the Edit Action as the default.To change the Default Action of a file when double clicked, Open Explorer, Select View, Folder Options, File Types, and then the file type you want to edit .
If there are multiple actions the Default is embolden
Scroll down to the file you want to change, Select edit, Highlight the action you want as default and press the Default Tab.