how-to configure X11 port forwarding between a Windows and Linux with Cygwin , mintty and

1. Install cygwin by defaults ( google download cygwin)
   Save the Cygwin setup.exe file into a dir you remember

2. Open the cmd.exe as Administrator. Press WinLog , type cmd.exe , right-click , choose Run as Administrator

3. Go to the dir where you saved the cygwin setup.exe, for example:
cd C:\Temp

4. Install the following packages:
setup-x86_64.exe -n -q -s http://cygwin.mirror.constant.com -P inetutils
setup-x86_64.exe -n -q -s http://cygwin.mirror.constant.com -P openssh
setup-x86_64.exe -n -q -s http://cygwin.mirror.constant.com -P xorg-server
setup-x86_64.exe -n -q -s http://cygwin.mirror.constant.com -P xinit
setup-x86_64.exe -n -q -s http://cygwin.mirror.constant.com -P xorg-docs

Install any other required dependancies ( packages ) required for those mentioned above.

5. Start mintty termminal. In the terminal start the connection to the remote host
export ssh_user=type_here_ssh_user_to_connect_with
export ssh_server='type_here_ssh_server_to_connect_to'

#access the instxance via ssh
ssh $ssh_user@$ssh_server

6. Ensure you have allowed X11 forwarding in the sshd_config file
vim /etc/sshd_config
 
AllowAgentForwarding yes
AllowTcpForwarding yes
X11Forwarding yes
X11DisplayOffset 10
X11UseLocalhost no

Restart the sshd daemon
service sshd restart

7. Ensure you have the xauth package
yum -y update xauth
apt-get -y update xauth
yum -y install xauth
apt-get -y install xauth

7. Exit from the server
exit

8. Configure the display environmental variable on you local machine
export DISPLAY=:0.0


9. Start the XWindows Manager on you local machine
startxwin &

10. Start ssh with X11 enabled
ssh -Y $ssh_user@$ssh_server

11. Verify
# install an app supporting X11 forwarding
yum -y install xclock
# and Action !!!
for i in {1..3} ; do bash -c "xclock &" ; done ;

you should get the 3 windows on the xclock app locally on your PC. If not you mileage varies, google the error message
if you cannot fix it within 10 minutes post a comment - probably the instructions here are not good enough ...