XWindow is not enabling !!!

Dear Experts,
Our system admin is struggling over a month with an issue regarding xwindow. RHEL 5.4 is our server OS. whenever I export Display with my machine IP and run xclock. It is not working. We are using DHCP. Please tell me what checks and actions should be taken from our sys admin point of view.

What OS is on your machine?

Already mentioned man.

You actually didn't. You said that RHEL 5.4 is your server OS but then mentioned "Your machine."

If you want help, specifically free help from volunteers, don't make it a mystery.

You have not mentioned what X server you are running or whatever else you have done.

Sorry. It's my mistake to get the question.
My Machine OS: Windows 7 32bit
X Window software: Hummingbird Exceed

have you tried to enable the remote X server with xhost?

1./tmp is full or not
2.Quota is already reached
3.Video card or resolution or monitor is misconfigured.
4.xfs service is running or not. Do These:
4.1.df -h /tmp /tmp is full remove the unnecessary file
4.2.quota username if quota is already reached remove unnecessary file from home directory.
4.3.Boot the System in runlevel 3. you can pass the Kernel Argument from boot loader.
4.4.Use command: system-config-display It will display a dialog to configure the monitor, Video card,
resolution etc.
5.Set the Default Runlevel 5 in /etc/inittab id:5:initdefault:
6.Reboot the System you will get the GUI login Screen.

How exactly are you attempting to start your X session? For example, did you configure Exceed to use XDMCP or are you starting a remote X session via ssh or some other method?

If XDMCP, your RHEL server system administrator has to grant permission for you to access the system. I am not in front of a RHEL5 box at the moment but I believe that the relevant files are: /etc/X11/xdm/Xaccess and /etc/gdm/custom.conf.

@all,
One thing I missed to inform that my office network is wifi enabled and we connect to the servers (which is in different location) through this wireless lan. Is this any problem?

@mark54g: yes I have tried by enabling xhost. as root I put xhost +

@getrue: I believe all the steps should be done in server machine. Is there any steps which I need to configure in my windows machine?

@fpmurphy: I am not sure and also not so much well informed about the topic you said. Would you please make it little bit easy for me to understand?