Many customers at some point request to force either the www or non-www version of their site to display in their visitor's browser. For example, you can have www.example.com or simply example.com display in an address bar.

There is a common thought that forcing one format is better for search engine optimization.

To force non-www to www version of your web site:

step 1: Edit your .htaccess file using your favourite ftp client.

step 2: Put the following content

#Force www: RewriteEngine on RewriteCond %{HTTP_HOST} ^example.com [NC] RewriteRule ^(.*)$ http://www.example.com/$1 [L,R=301,NC]