Hello, I've found the solution for my problem: sudo yum install xorg-x11-xinit Once I've done that, then started Xming with -ac and PuTTY with X11 Forwarding enabled, then the variable DISPLAY got set to localhost:10 automatically and I could run X-programs Your advice with NX has worked too, thank you, Les: sudo yum install freenx sudo cat /etc/nxserver/client.id_dsa.key (paste the key into Windows NX client prompt) Regards Alex On Tue, Jun 15, 2010 at 9:41 PM, Les Mikesell <lesmikesell at gmail.com> wrote: > What you are doing should work if putty is really forwarding, but if you > intend to do much remote X work, I'd recommend installing the freenx > package on the CentOS side and running the windows NX client that you > can download from http://www.nomachine.com. The only quirk I've found > is that it generates a unique keypair during the install so you need to > cat /etc/nxserver/client.id in a putty session, and cut/paste it into > the nx client config (click configure, then the 'key' button). It takes > care of running over the ssh port for you and gives much better > performance than normal remote X access.