setup vnc4server

reference from Ubuntu Forums
HOW TO: setup vnc4server

1. setup XDMCP:
　　click System -> Administration -> Login Window
　　click Remote tab
　　select "Same as Local"
　　click "Configure XDMCP"
　　remove check from "Honour indirect requests"

2. configure remote greeter:
　　$ sudo gedit /etc/gdm/gdm.conf

find the following:
　　(1) [xdmcp] section, set enable as true
　　　　　Enable=true
　　(2) # RemoteGreeter=/usr/lib/gdm/gdmlogin
　　　　　enable it(remove the comment)

3. Install required packages:
　　$ sudo apt-get install vnc4server xinetd

4. Set the VNC passwd
　　$ sudo vncpasswd /root/.vncpasswd

5. Define the VNC service criteria:
　　$ sudo gedit /etc/xinetd.d/Xvnc

service Xvnc
{
    type = UNLISTED
    disable = no
    socket_type = stream
    protocol = tcp
    wait = yes
    user = root
    server = /usr/bin/Xvnc
    server_args = -inetd :1 -query localhost -geometry 1024x768 -depth 16 -once -fp /usr/share/X11/fonts/misc -DisconnectClients=0 -NeverShared passwordFile=/root/.vncpasswd -extension XFIXES
    port = 5901
}

Save it!

NOTE: You can change the port number here, it changes what you use to connect to the server. For example, if you chose port 5959, you can connect to your Ubunutu using RealVNC on Windows XP by typing: 192.168.0.101:5959

6. Reinitialize the service with new criteria:
　　$ sudo /etc/init.d/xinetd stop
　　$ sudo killall Xvnc
　　$ sudo /etc/init.d/xinetd start

7. Test the connection:
　　$ vncviewer localhost:1

Also reference
Ubuntu 7.10系統配置vnc4server遠程桌面