By default, the connection with the root account is not possible because it does not have a password and the SSH server is configured so as not to allow connection with the root account.
It happens that for some operation / installation the root account is required.
In this tutorial, we will have how to configure Ubuntu / Debian in order to connect with the Root account in SSH.
Set a root password
sudo passwd root
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
Allow SSH connection as Root
Edit the following file: / etc / ssh / sshd_config
Comment the following line:
Restart the SSH service
sudo service ssh restart
You should now be able to log in as root with Putty and WinSCP.