I highly recommend that anytime you are going to utilize the SSH RSA Keys instead of password based login, that you first test that your login works using your newly generated key pairs before disabling password-based login. You don’t want to edit the config file for anything other than adding the “PasswordAuthentication no” statement. Again, that step should only be done after you confirm a successful login using your key(s). You really shouldn’t have to touch the sshd_config file except to add that one line.
Did you follow the rest of the steps pertaining to adding the key to the authorized_keys file? I actually recommend you do that manually using VIM or nano to paste in the key, rather than using the “copy id” command if you’re able.
Finally, even if you don’t use Putty due to compatibility issues with Windows 7, you may still find the “Puttygen” and “Pageant” utilities useful for generating the appropriate format for your keys - as well as actually utilizing the key during your connection.