With my windows PC and Rpi3B I make, in addition to PuTTY, often use of WinSCP (https://winscp.net/eng/docs/start) (https://winscp.net/eng/download.php). It's freeware. Under the protocol "SCP" I go to the IP address of my Rpi and can open a file by double-clicking on it, edit and save it. Personally, I find this is a quick way to make changes.
