How can you check if mod rewrite is enabled?
From Joomla! Documentation
Many problems with search engine optimization (SEO) arise from the fact that a host has not enabled mod_rewrite on the server.
1. Enable SEO in your administrator! (administrator > SEO > Enable > Save)
2. Rename your htaccess.txt to .htaccess, or use your existing .htaccess file.
3. Place ONLY the following lines in your .htaccess file.
Options +FollowSymLinks
Redirect /joomla.html http://www.joomla.org
4. Point your browser to: http://www.mysite.com/joomla.html
(Replace 'mysite.com' with your site's actual URL.)
5. If you are redirected to www.joomla.org, mod_rewrite is working. If you get an error, mod_rewrite is not working.
6. Note: if your site is located in a sub-domain, for example "test" you need to modify .htaccess as follows:
Options +FollowSymLinks
Redirect /test/joomla.html http://www.joomla.org
