Changed Comment Module and database table - how to revert changes? Yesterday, I posted this thread which was subsequently locked for being too localized. I think this is much more searchable (and I still need help!) but I'm sorry for the bad thread.

Like mentioned in that thread, I changed different files in the comments module folder and added columns to the database table. This sort of disabled comments, both the settings in page content settings and their appearance on the page normally.

I tried to fix this by: uploading a completely new 'comments' folder (I have a back up if that was a bad idea) from a new copy of the core, and deleted those table fields. Still no sign of fixing any of the problems I created.

How do I return the comments to their normal setting so I can approach the altering I was planning on doing the right way this time?
First: Do not hack core!

To restore your site to a stable state, revert to the default theme, back-up your database and the sites/ sub-directory and anything below it.  Then download a fresh copy of the core and install it. Finally, restore the sites/ sub-directory, your database, and the theme.

Having extra tables in the database that Drupal does not know about does not do any harm, but you may drop those tables that you created yourself before backing up the database.