First login to the administration panel and go to
System > Global Configuration
In the “Site tab” you will have to do some changes for the SEO Settings. Use the “Yes” option for Search Engine Friendly URLs and URL rewriting. If the URL rewriting is not working, probably your web host did not activate the mod_rewrite module on the Apache server. Contact them to make these changes for you.
Now find the htaccess.txt file in the main folder where your site is installed and rename it to .htaccess
You are almost done, but there is one more little thing to do, to remove the index.php from the urls. You will have to edit the .htaccess file and find the following line:
# RewriteBase /
Remove the “#” from the line and if you have installed your joomla site in a sub-folder (ie: http://yoursite.com/joomla ), insert the sub-folder name after the “/”
If joomla is installed in the root folder, you don’t need to add any sub directory to the code, just use it like this:
Now check your site and see the effects of the changes.