To get started connecting with SFTP please download winscp and unzip/install the program.
Launch winscp and select SFTP connection from the drop down.
Enter the servers Host name, User name and Password or optionally key. See the next section to configure ssh key based access.
To configure a private key, select Advanced, or move on to Login.
Select SSH -> Authentication and load the private key file used to SSH into the instance. **NOTE: the key should be in the putty .ppk format file extension.**