Clean URL Enabling in Drupal 7

To enable clean url in Drupal 7, we need to do two primary steps

1. Drpal home directory should have a .htaccess file.
2. Uncomment the RewriteBase line in the .htaccess file.

# If your site is running in a VirtualDocumentRoot at http://example.com/,
  # uncomment the following line:
   RewriteBase /

Then we need to check the clean url and save it (admin/config/search/clean-urls)