If Joomla is installed in its own folder, uncomment "RewriteBase /" and enter the Joomla folder name after the backslash. Example: RewriteBase /joomla
2. Make sure that Mod_rewrite is working. Check that the line shown below in the file "apache/conf/httpd.conf" is uncommented. If necessary, uncomment the line and re-start the Apache web server.
LoadModule rewrite_module modules/mod_rewrite.so
3. In Global configuration, select yes to all three SEF options. The action of the three parameters is as follows:
Search Engine Friendly URLs. Converts the URLs from the native Joomla! format to the SEF format.
Use Apache mod_rewrite. Uses the Apache "mod_rewrite" function to eliminate the "index.php" portion of the URL. If you don't want to use mod_rewrite, set this to "No" and don't rename the htaccess.txt. The SEF URLs feature will still work. The only difference is that you will see "index.php" in the URL, for example, http://www.yoursite.org/index.php/faq.html.
Add suffix to URLs. Adds ".html" to the end of URLs.