I was using PuTTY at a screen resolution of 1600x1200, in which the default font setting caused the text too small to read. So I changed the font to 12px size, and it looked fine, but when I exited it and logged in back again, the font settings were gone. Then I figured out that you have to change the font settings and then come back to Sessions page and enter “Host Name” and save the session. So next time , you select the saved session and click on load to login to the host with the saved font settings.

Putty settings