Hello Saurav,
If folks do not have knowledge about file types, then that is what we are for to help with. They only need to post and provide details about their issue for us to be able to help.
I didn't put all of them in the same file because it would be to large, and everyone may only want one or so file extensions reset to default associations and not all of them. This way it makes it much easier to only download the ones you need to apply.
I do not work for Microsoft. I'm only an individual that helps people by providing fixes like this, and was given a
MVP award by Microsoft for doing so.