To remove index.php from URLs you will need to enable the Use URL rewriting in Joomla 3.x and rename htaccess.txt to .htaccess. This is Apache users only. The IIS 7 users have to rename web.config.txt to web.config and install IIS URL Rewrite module before activating.
Do the following to enable Use URL rewriting in Joomla. Logon to your Joomla dashboard. Click on Global Configuration link under SYSTEM tab. Click on Site tab and then
go to SEO Settings. Set the Use URL rewriting option to Yes and set the Include Site Name in Page Titles to “After”. Then Save the changes.