Error: cannot open display: localhost:0.0 - trying to open Firefox from CentOS 6.2 64bit and display on Win7

Question

I am on a Windows7 machine and I'm trying to get firefox to open on the centOS machine, but be displayed on my current screen. When typing firefox in terminal, I am getting the following error:

Error: cannot open display: localhost:0.0

To setup the display I used the command

$ export DISPLAY=localhost:0.0

Some site suggested using the following, but it didn't work either:

$ export DISPLAY=:0.0

I am using PuTTY and I have the Enable X11 forwarding check box checked and XMing is running on Windows. Additionally, the sshd_config on centOS file seems to be setup properly as well:

$ cat /etc/ssh/sshd_config |grep -i x11
#X11Forwarding no
X11Forwarding yes
#X11DisplayOffset 10
X11UseLocalhost yes

I've looked over numerous pages and searched StackOverflow as well, but none have managed to help me in any way. Thank you in advance.

Answer 1

So, it turns out that X11 wasn't actually installed on the centOS. There didn't seem to be any indication anywhere of it not being installed. I did the following command and now firefox opens:

yum groupinstall 'X Window System' 

Hope this answer will help others that are confused :)

Answer 2

I faced this issue once and was able to resolve it by fixing of my /etc/hosts. It just was unable to resolve localhost name... Details are here: http://itvictories.com/node/6

In fact, there is 99% that error related to /etc/hosts file

X server just unable to resolve localhost and all consequent actions just fails.

Please be sure that you have a record like

127.0.0.1 localhost

in your /etc/hosts file.