Require First and Last Name on Comments in Drupal 7
In Drupal 7, Comment fields are managed the same way Node fields are managed. 

Go to structure->Content types-> edit link. If comment is enabled for selected content type, It will add a tab for "comment fields" on top besides manage fields tab.

For article content type url will be "admin/structure/types/manage/article/comment/fields" and tab looks like the image attached below.