I'm unable to login to my Fedora 7 system. From SSH with either password or certificate, any user including root. No better from the console, and I see that the failure occurs upon entering any username including root, before any chance to enter password.
Recent history: It has been working well for months, then two days ago I tried to install NX server (free version) from nomachine.com. I was unable to connect and thought I'd get back to it later. Also I accepted a general update of my software.
I'm quite computer-literate, but still new to Linux after these few months.
Thanks in advance for any advice.