Allowing non root users to login through putty

 vi /etc/ssh/sshd_config append last line AllowUsers erpuser

service sshd restart

mkdir /home/erpuser/.ssh

cp ~/.ssh/authorized_keys /home/erpuser/.ssh/authorized_keys

chown erpuser /home/erpuser/.ssh/authorized_keys

su erpuser

chmod 600 /home/erpuser/.ssh/authorized_keys

exit

service sshd restart