Hi,
it looks like the php extension isn't enabled. There should be a php.ini file somewhere in the easyphp installation.
Make sure that a line containing
extension=php_mysql.dll
exists in the php.ini. Remove the ; in front of the line if it already exists and restart apache. You can enable other extensions you need the same way.
I never installed easyphp so I don't know exactly where the php.ini file is.
Thomas