Out of the box there is practically no support for MSSQL. Drupal 7 there was an attempt to do support it driven by the Commerce Guys, but that work migrated to a contrib module and is not in core. Here is a quick rundown of compatibility.

**Drupal 6**: Not possible

**Drupal 7**: Possibly with the MSSQL Layer module called [SQLsrv][1]. But be prepared for issues when using contrib modules, some will not work because many modules write out SQL commands and run them with [db_query][2] instead of the abstraction layer for performance reasons - especially complex queries.

**Drupal 8**: Not possible.

If you really want to get the most out of Drupal with as little headache as possible, run MySQL or even MarianDB on Windows.

  [1]: https://www.drupal.org/project/sqlsrv
  [2]: https://api.drupal.org/api/drupal/includes%21database%21database.inc/function/db_query/7