A while back I wanted to do something with Wordpress that seemed like it should be the easiest thing in the world to do, like there should be a setting or something to change to turn off comments, but my search ended in disappointment at the thought that I would have to scrounge through and remove all the code that displays comments...I really hate when things aren't made easy for me.
Anyway, here's how it's done...
1. Open index.php and remove this:
2. Open single.php and remove this:
3. Open archive.php and remove this:
That's it, you're done, unless you have another theme that you're using, in which case you need to scan all your blog pages for anything related to comments. If you find something, open whatever template that page is using and remove any lines of code like what's above.