This is something I completely missed but for a good reason.

I was trying to mess around with public key authentication (for an easy and secure way to log in) on Windows. I’ve done it many times on Linux -> *nix but I never messed around with Putty. Putty is a great program with a terrible, terrible interface. Case and point, I got my public key working but it was still prompting me for the username. Where do I put the username?!

There’s a text box called hostname that you can put the username in (makes sense right). See below

Very confusing.