Open the PuTTY client and choose the server information for your desired connection.
a. If you have no saved sessions or are entering the session information for the first time, enter the hostname "cunix.cc.columbia.edu" in the "Host Name (or IP address)" text field. The port should default to 22. For "Connection type", select SSH.
Host Name: cunix.cc.columbia.edu
Port: 22
Connection type: SSH
b. If you just entered the session information, save your entry now by entering a name like "cunix server" in the "Saved Sessions" text box and click Save.
c. In the future, when you start up PuTTY, select the saved session name ("cunix server") and then click Load to automatically fill in your connection settings.