The SQLSRV extension can be used on the following operating systems:
The SQLSRV extension requires that the Microsoft SQL Server 2012 Native Client be installed on the same computer that is running PHP. If the Microsoft SQL Server 2012 Native Client is not already installed, click the appropriate link below to download it:
The SQLSRV download comes 8 driver files, four of which are for PDO support.
The most recent version of the driver is available for download here: » SQLSRV download.
For more information about SQLSRV requirements, see » SQLSRV System Requirements.
If you get the error "sqlstate [imssp]: this extension requires the microsoft odbc driver 11"
Msodbcsql.msi should be installed, otherwise it does not.
Take the x64 version and x86 architectures 64 for 32 architectures.
https://msdn.microsoft.com/en-us/library/jj730315%28v=sql.110%29.aspx