Windows 7: How to modify what program opens a batch file

Default Programs Editor was created for this purpose! From the site:

File Type Settings:

• Add, Edit, and Delete context menu items
• Edit file type information (such as icon and description)
• Change an extension's associated file type

It also does Autoplay handler editing, and Default Programs editing. And it installs as a Control Panel applet, which makes it discoverable from Windows Search, so you can forget about it until you need it.

Also, it doesn't require administrative privileges for most operations (but it is UAC compatible).

(In the interest of full disclosure, I wrote this program!)

In many programs you can set file types associated with the program itself from settings. For example in Notepad++ you can go to Settings -> Preferences and select tab File Association. There you can add files that should be associated with notepad++.

This is not direct answer to what you asked but it should accomplish the same task. In case the program you want to set associations with doesn't have this option you will have to use your method.