This simple Plugin removes the website field in your comments and also hides all the hyperlinks from comment author user names.
Remove links from comments plugin does only two things.
It removes the Website field from the comments - modifies comment_form_default_fields
It hides the the hyperlink under comment author box - modifies the behavior of get_author_comment_link
So all the future comments will not have the website field at all and you don't have to worry about the comments that are already on your website as it will automatically hide them showing only the comment authors name as a plain text.
Anywhere comment author names are displayed on your website.