PuTTY does not write its settings to a file, for people who wish to install this on an USB stick poses a challenge. When you run putty on a system that never ran it before, it will not have any of your saved settings. Only solution (that i know of) is to merged your registry settings with the system you running it on. (a bit intrusive.) So in just seven easy steps you can now have your PuTTY settings on your USB drive.
From your Windows start panel, click on “run”
Type “regedit” in the your run box.
Press “CTRL-F” (this will bring up the search box)
In the search box type “SimonTatham” (no space)
Click off Values and Data
You should now have the SimonTatham highlighted in your registry
Right click and select “Export”
I saved mine to the desktop and named it something that I would not forget what it it.
Once you have the file you can move it to your USB key and import or merge
it to which ever system you are working on.
That’s it, you’re done!