Windows Download Page To download the 16.210 Client for Windows click here. To download the 12.1 Client for Windows click here. To download the 11.063 Client for Windows click here. To download the 10.014 Client for Windows click here. To download the 9.126 Client for Windows click here. Once the installation is complete click here. When the Login screen appears, simply enter your user ID and password and click Login. For information about the Windows FirstClass client click here.