Here is how to disallow comments in WordPress. Please note that this applies to version WordPress 3.6.
To disallow comments for new posts:
- In the admin, go to the Discussion section under Settings on the left.
- Uncheck the "Allow people to post comments on new articles" option.
To disallow comments for existing posts:
- Go to the Posts section.
- Check the checkbox to the left of the Title column to select all posts.
- Click the Bulk Actions menu above this checkbox.
- Select the Edit option and click Apply.
- Select the "Do not allow" option in the Comments drop-down menu.