This extension is EXPERIMENTAL. The behaviour of this extension including the names of its functions and any other documentation surrounding this extension may change without notice in a future release of PHP. This extension should be used at your own risk.
This extension is not available anymore on Windows with PHP 5.3 or later.
On Windows, you should use SqlSrv, an alternative driver for MS SQL is available from Microsoft: » http://msdn.microsoft.com/en-us/sqlserver/ff657782.aspx .
If it is not possible to use SqlSrv, you can use the PDO_ODBC driver to connect to Microsoft SQL Server and Sybase databases, as the native Windows DB-LIB is ancient, thread un-safe and no longer supported by Microsoft.