Problem scenario #1
You try to SSH to a Windows server with OpenSSH. You get "Permission Denied."
Solution
Go to the Windows server. Go to Server Manager -> Tools -> Computer Management -> Users and Groups. Double click on the user you are trying with. Uncheck "User must change password at next log on." This setting will not allow an SSH connection to happen.
Problem scenario #2
ssh-agent service is running on a Windows server with OpenSSH. From a Linux sever you use this command: nmap -p 22 x.x.x.x #where x.x.x.x is the IP address of the Windows server. You find that the port is closed (but not filtered). You cannot SSH to the Windows server. What is wrong?
Solution
From a PowerShell prompt, run this: start-service sshd
Now port 22 will show as open if you try the nmap command again. Now you should be able to ssh to the Windows server.
FYI
These directions have a variation of this step of running "start-service sshd" as optional. It is not an optional step.