Yesterday I told you about a terminal program for connecting to computers across the internet or your local network. One of the protocols it supports is SSH, which is a secure and encrypted way of remotely accessing a computer's command line.
Linux systems, and lots of other servers, use SSH a lot. It lets you control the remote server if it doesn't have a Graphical User Interface available. Also, if Windows is not behaving properly and you're unable to log into a Windows computer via Remote Desktop, SSH means you can still access the machine via a command line. From where you can try restarting it, perhaps, or delete some of the files which you think might be causing the issue.
To be able to access a Windows computer remotely via SSH, that computer needs to be running an SSH Server utility. This is not something that everyone will want to do, but if you are technically minded and/or you provide tech support for computer users, then installing an SSH Server on those PCs is a really good idea. It gives you a chance of accessing those computers remotely, even if they don't boot properly into Windows.
Although Windows doesn't include an SSH Server product as standard, there are some commercial versions available. One of those, from Bitvise, is even available free of charge for non-commercial use. Just head to https://www.bitvise.com/ssh-server-download in order to download the installer, which is a 14 MB file. The site is rated as reputable by Web of Trust, and VirusTotal claims that it's free of all malware.
Once installed, you can now connect to the remote computer using an SSH terminal or client. Note that you will also need to open port 22 on the remote computer's firewall. If you don't know how to do this, and you don't know the implications of doing so, you should take further advice before proceeding as this can be a security risk.
Incidentally, having SSH available has proved really useful to me on at least one occasion. I needed to access a remote Windows computer, but a problem with a recently installed update was preventing me from doing so. Access via Remote Desktop simply wasn't working. Using SSH, I was able to connect to the remote computer via its command line in order to reboot it, after which it worked perfectly.