At the end of the instance creation, AWS guesses “root”. Tried that, no go.
Many articles and forums say it should be “ubuntu” so tried that too, but it generates the same error in Putty.
PuTTY Fatal Error
No supported authentication methods available (server sent: publickey)
In the Putty window under that popup error, it says “Server refused our key”
Of course I double checked the keypair matches. I generated it myself using PuttyGen and only gave AWS the public and saving the private locally and telling Putty where it is.