sqlsrv_connect issue

I am getting the "Call to undefined function sqlsrv_connect()" error using the  new drivers. I have read many, many posts on other sites about this problem, but still cannot get it resolved.

PHP 7.0.15

Windows 10

IIS Express 10

I am using "extension=php_pdo_sqlsrv_7_nts_x64.dll" in my php.ini file

phpinfo() produces a section for PDO and pdo_sqlserv. There is no section for sqlserv. The registered php streams does not have any reference to sqlserv.

Any ideas?