php artisan migrate could not find driver in windows platform

I ran php artisan migrate from command prompt and got the error message:

In Connection.php line 664: could not find driver (SQL: select * from information_schema.tables where table_schema = l6 and table_name = migrations)

In Connector.php line 67: could not find driver.

Please, i am new to laravel, using laravel 5.4, php 7, xampp and windows platform. I have checked my php.ini, extension=mysql_php_pdo.dll is uncommented. my env file is properly filled. tried doing something to make apache and cli use same php.ini file.. yet nothing works. Please assistance is highly needed and much appreciated.

Thank you.