If you have already install Sugar version 5.0, then you will need to migrate the application to use the FreeTDS driver. A pre-requisite for migration is that you are using Sugar version 5.0 with SQL Server 2005 on Apache with a PHP version 5.1.x or higher. This means that your current php.ini file and config.php file for SugarCRM instance should already reflect the necessary changes to run SugarCRM with SQL Server. The assumption is that there is data in the tables with multi-byte character values. You can also choose to create test data from a new 5.0 instance. This can be setup through the installation process by choosing to populate multi-byte character seed data with the installer. For more information, see "To migrate Sugar to FreeTDS driver".
There are three separate folders for three different versions of PHP (5.1.x, 5.2.x, 6.x). The php_dblib.dll file is the FreeTDS dynamic link library file. Your extension directory is the value for the extension_dir key in the php.ini file. Typically, it is located in the ext folder. Ensure that you choose the appropriate version of the FreeTDS dynamic link library to use. They are organized according to PHP versions under the Drivers folder.
Place the freetds.conf file in the c:\ directory of your Windows operating system.
Copy ntwdblib.dll and msvcr71.dll to the Windows/SYSTEM32 folder for runtime extension support and verify the accuracy of the ntwdblib.dll file.
The msvcr71.dll file is also included in the freetds.zip file and should be copied into the Windows/SYSTEM32 folder as well. The subdirectories of your Apache installation directory may also contain copies of the ntwdblib.dll file. Ensure that the versions of the ntwdblib.dll file in those folders match the one you have placed in Windows/SYSTEM32. If you are unsure, you may also rename the ntwdblib.dll files under the Apache directories to be safe.
For My SQL and SQL Server database, by default, Sugar selects the Admin User as the database administrator. But you can specify a different user as the database administrator. To select an existing user, select Provide existing user. To create a new database user, select Define user to create.Enter the database user name and password in the fields that display below. Reenter the password to confirm it.