We have found that the NIC SFTP Agent wants you to run under a Domain Account. We do not want to use this as our account password expiry is very rigid. Since this agent is based on PuTTY, we have found it better to do the following.
Install the SFTP Agent on the machine using any account with administrator rights.
Make your intial connection the EnVision machine using the psftp -i private.ppk -l nic_sshd -v enVisionIPAddress
Accept the host key then quit. This will populate information in the registry about the server.
Open the registry and add the registry values to
you can copy the information from your own registry hive as the example
SimonTatham is the author of PuTTY.
This way the SFTP Agent runs under the local SYSTEM account and doesn't need a Domain ID to run the service
I hope this helps