Telnet in Linux

[Taximus]

Hello everyone. I want to share with you a story about amasing student.
I knew one girl, she had Windows XP installed on her computer. One day her PC didn't work
and she worried about that. She tried to turn it on, it turned and then it didn't show
anything. So girl could not understand what had happened. In the same room there was
linux specialist(he was using debian). He asked girl's PC, then he connected his computer
to girl's PC and he did smth for 10 minutes and fixed the problem. I was so amased. I've asked
him:

How did you do that?

He answered:

Read about telnet.

I tried to search on google
but I didn't find anything(any useful information). I have known that telnet is a utility
which enables you to connect to other PC (which has telnet) and you can do some staff on other PC.
I heard that on the most computers telnet is not launched by default. So, this guy was lucky
or he knew how to do that. Can anyone explain me how to do that? I wanna become specialist as
he is. This is very cool. Can anyone suggest me something? Maybe some useful links or your
experience in that?
Thank you for your awesome help.

[mike_2000_17]

telnet is just one of those basic remote login methods. It is not used very much because it is not secure (not encrypted). Most remote access work is usually done using SSH (or similar secured shells). Both methods basically allow you to just login to a computer, remotely, and be able to use the "shell" (or command prompt).

In both cases, the computer receiving the connection must have a server program waiting to accept such connections. Most personal computers (i.e., not plugged to a business / academic network) will not have those programs running by default (must be installed and enabled). But if the computer is setup as an in-network computer (or workstation), these programs are usually started up very early in the start-up (since they don't require any graphics driver and user interface, which are the usual culprits of difficulties to start-up a Windows machine) because they are used for connections to log in to the campus network.

So, if you have a Windows computer that is usually plugged to a business or school network, and that seems to stall half-way through the startup, then it is reasonable to try to telnet / ssh to it and fix the problem that way. Of course, once you are logged in remotely, you still need some good know-how on the Windows system to find and fix the problem with it, with command-line access only. That's the hard part in my opinion.

If you want to "learn" to use this, you need to learn to be confortable with the command-line terminal. Get a Linux installation, and play around with shell commands and scripts. The SSH / Telnet parts are just a few of the thousands of commands you can play with when you have a decent shell, like bash on Linux.