Drupal Error - Fatal error Class 'PDO' not found

Your drupal powered website may show error message like PDO not found.
The error message may be something like this:

Fatal error: Class 'PDO' not found in /home/username/public_html/includes/database/database.inc on line 184

Solution

1. Create a file php.ini in public_html folder
2. Add following code:
   

   extension=pdo.so
   extension=pdo_mysql.so

3. Save php.ini file

Done!!!