I've done all the basic changes that are required when you move a WordPress installation from a sub directory to the root directory.
added lines to wp-config.php
I transfers the files to root Directory, and
I only got the home page up, all the other pages direct to sub directorys 404 error page. I also can't access the dashboard.
I even tried replacing the .htaccess file you had with the default .htaccess file for WordPress, but that too didn't fix the issue. I checked and confirmed that ymy siteurl and home url are pointed to my domain root directory and not to the sub-directory.
Any way to correct this?