From my Windows PC in command line (cmd.exe) I am connecting to a remote high performance computing cluster (RedHat 7 from my windows cmd terminal) and would like to open Firefox for uploading some data.

I connect to the cluster using,

ssh -Y [email protected]

In order to run Firefox I run the following commands,

module load firefox

firefox &

and get an error,

Error: no DISPLAY environment variable specified

I have tried using the following commands but they don't work,

export DISPLAY="localhost:10.0"


export DISPLAY=""

Looking forward.

  • Please try ssh -X -Y user@host. I don't think Y alone is enough. Commented Mar 25, 2021 at 19:08
  • I tried this but it gives me the same error. Seems like there is a solution to this (here: stackoverflow.com/questions/12356425/…) but it's not working on my windows cmd terminal.
    – GISEnthu
    Commented Mar 25, 2021 at 19:13

1 Answer 1


As far as I know Windows by default does not include an X11 server to enable X11 forwarding. I might be wrong though. You cannot forward X11 applications without it. Check this for possible solutions:

  • So I installed Cygwin/X (from x.cygwin.com) and then logged in again with ssh -X -Y [email protected]. But I still get the same error message (no DISPLAY environment variable specified) when I try to start firefox.
    – GISEnthu
    Commented Mar 25, 2021 at 19:32
  • Try using putty instead: chiark.greenend.org.uk/~sgtatham/putty/latest.html - make sure X forwarding is enabled in an SSH session options. Commented Mar 25, 2021 at 19:35
  • Good thing is I could connect with Putty and the error message is slightly different. It now says, ' cannot open display: localhost:12.0'. I also tried export DISPLAY="localhost:10.0" and export DISPLAY="" but they don't work.
    – GISEnthu
    Commented Mar 25, 2021 at 19:44
  • I got something new. PuTTY X11 proxy: unable to connect to forwarded X server: Network error: Connection refused. Error: cannot open display: localhost:14.0
    – GISEnthu
    Commented Mar 25, 2021 at 20:32
  • Your X11 server on Windows should tell you what is right display value, you cannot choose arbitrary value there. If you would run xterm in your cygwin, then you can see value with echo $DISPLAY, DISPLAY value is automatically passed to remote SSH host if you request X11 forwarding with -Y or -X. The remote host can of course disable X11Forwarding completely or for specific user.
    – Jiri B
    Commented Mar 25, 2021 at 21:27

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