Answer by Mateng for Is there a way to permanently set the font and window size in PuTTY?

This works with Kitty Portable, I don't know if it applies to Putty Portable:

I had 51 preconfigured sessions and wanted to change window size for all of them. There is no settings option to achieve this, but you can do this:

• Get a text editor that can search and replace in files (PsPad / Notepad++, ...)
• Search and replace in all configuration files in this folder:C:\[Kitty/Putty Installation directory]\Sessions\
• Examples:
  • For window height, change TermHeight\24\ to TermHeight\40\
  • For window width, change TermWidth\80\ to TermWidth\120\
  • ... and so on. Font is Font\<Fontname>, Font size is FontHeight\10 ...

Needless to say Putty might be installed on another drive and you are allowed to choose your own values.