Suppose that you have a Windows system and that you want to connect to a remote Linux Ubuntu machine; suppose that you also want to run some applications of that machine, having at disposal also their graphical interface.
First step: configure the Windows system
Install Xming. Use a simple google search for “sourceforge xming x server windows”. When asking for the fonts to be installed in the “Custom installation” stage, we would recommend to install all the fonts.
Second step: configure the Linux system.
Install the openssh server: sudo apt-get install openssh-server.
Open the file etc/ssh/ssh_config, uncomment the ForwardX11 line and change the option from “no” to “yes”.
After that, use Putty to connect to the linux machine via ssh. In particular:
Session -> Host Name -> put the address of the linux system;
Connection -> SSH -> X11 -> X11 forwarding -> Enable X11 forwarding.
As an example, in the terminal, type
Xclock & (do not forget “&”).