Issue :
When I set Search Engine Friendly URLs to “YES” and Use Apache mod_rewrite to “NO” in Global Configuration, URLs look like this with an index.php in the URL:

http://domainame.com/index.php/mylink.html

If I turn Use Apache mod_rewrite to YES, the URLs look correct, but give 404 pages.

http://domainame.com/mylink.html

Solution :
Rename htaccess.txt file to .htaccess in root folder