With some trial and error this morning I found out the known host file needs to be called "known_hosts" with no file extension and needs to contain the hex value of the key, and the private key needs to be called "private.key" and is a KEY file type.
To find the known hosts value, I opened up regedit navigated to HKCUR\Software\SimonTatham\PuTTY\SshHostKeys and copied the value.
To find the private key, in the server I found it in /etc/ssh. There was a couple of different keys to choose from and I ended up using the RSA key.