[Solved] MSSQLConnection with windows authentification lazarus / 16-Databases ---------------------------------------------------------------------- Zoran · 2019-01-16 12:26 By following the wiki, I installed FreeTDS dll files and I managed to connect to MSSQLServer using sql server login. However, I don't know how to connect using Windows authentification. Is it possible at all with MSSQLConnection? ---------------------------------------------------------------------- Remy Lebeau · 2019-01-16 23:57 Simply leave the UserName and Password properties blank.  This is stated in the TMSSQLConnection documentation: https://www.freepascal.org/docs- html/fcl/mssqlconn/tmssqlconnection.username.html https://www.freepascal.org/docs- html/fcl/mssqlconn/tmssqlconnection.password.html QuoteTMSSQLConnection specific: if you don't enter a UserName and Password, the connector will try to use Trusted Authentication/SSPI (on Windows only). SSPI is how MSSQL uses Windows authentication. ---------------------------------------------------------------------- Zoran · 2019-01-17 14:00 Ah, so simple, I missed it in docs.  Thank you, Remy, yes it works.