While hosting official website,localhost not opening.Error display stating "Your PHP installation appears to be missing the mysql extension which is required by wordpress" provided that Apache and MySql are running.RESPECTIVE VERSIONS ARE OF SOFTWARES BEING USED. XAMPP 7.0.8 MYSQL 5.6.24 APACHE 2.4.18 WORDPRESS 5.7.1 PHP 7.0.8
I think you don't have the MySQL extension for PHP activated, even if you have PHP and MySQL installed.
Check that this line is uncommented in your php.ini file (by default : xampp\php\php.ini)
extension=php_mysql.dll
(Reload XAMPP if necessary)