Here's what I did to break it:
In the Dashboard, I changed SiteURL and HomeURL from "http://www.adamgoralDP.com/wp" to "http://www.adamgoralDP.com" without understanding the consequences...
Soon, http://www.adamgoralDP.com/wp went offline and I got the 404 error when tried to login to "http://www.adamgoralDP.com/wp-admin".
I've tried the "Edit Config.php" and "Edit Functions.php" methods as described here: http://codex.wordpress.org/Changing_The_Site_URL. Config.php didn't help, but Functions.php at least got the site (http://www.adamgoral.com/wp) displaying correctly.
I'm not sure what else to do. Site/wp-admin and site/wp-login return the same 404 error message when I try to access them. The website seems to be fully functional, I just can't log in to it!
I also tried to disable plugins (no help) and ensure film permissions were set to 755 as described here: http://www.techzoomin.com/wordpress-login-issueswp-admin-showing-404-error-page/
Furthermore, I was unable to find an .htaccess filll in my WP root directory to replace.
Any advice would be a huge help!