Yesterday our Product Manager faced a strange problem on his Windows 7 box. He created a site (which was a PHP application) but was not able to browse the site using http://localhost. He was getting HTTP status code 503 (Service not available). When I debugged his machine I found that following things hold true:
The SQL Server team just announced the release of their latest PHP driver for SQL Server. Details about the release can be found at http://blogs.msdn.com/b/sqlphp/archive/2010/08/04/microsoft-drivers-for-php-for-sql-server-2-0-released.aspx.