function CheckMSSQLServer(fServerName, fUserName, fPsw : string) : Bool;
var
  wDb : TDatabase;
begin
  // Check if MS SQL Server is reachable
  // Важно! BDE Должна быть установлена
  Result := False;
  wDb := TDatabase.Create(nil);

  with wDb do
  begin
    DatabaseName := 'wDbDatabaseName'; // arbitrary name, must be unique
    // in current Session
    Params.Values['SERVER Name'] := fServerName;
    Params.Values['USER Name'] := fUserName;
    Params.Values['PASSWORD'] := fPsw;
    LoginPrompt := False;
  end;

  try
    wDb.DriverName := 'MSSQL';
    try
      wDb.Connected := True;
      wDb.Connected := False;
    except
      ShowMessage('Server is not reachable');
    end;
    Result := True;
  finally
    wDb.Free;
  end;
end;