Disable all comments from all pages (attachment pages)

Hi guys,
I would like to disable all comments from all the pages of my web site. I have uncheck all the boxes in setting>discussion and also in the single article pages. Everything is working fine except for the pages generated by the media (attachment pages). I still continue to see the comment form of the theme with these fields:
Your name*; Your email* ; Your web page; Your comment*

What kind of file of the theme I have to check to fix this problem? I’m not good with php can you help me? Thank you! Bye :)