x server doesnt started automatically and neither it is starting manually through startx command.
even at the time of installation i installed RHEL5 through text mode.

startx displaying following errors:

data incomplete in file /etc/X11/xorg.conf
at least one device section is required
(EE)problem parsing the config file
(EE)error parsing the config file

fatal server error:
no screen found
XIO: fatal IO error 104(connection reset by peer) on X server ":0.0"
after 0 requests (0 known processed) with 0 events remaining.

please help it feels like handicapped w/o GUI

As root type system-config-display
Then make sure 5 is the default runlevel on boot.

no it didnt worked

couldnt start x server on card 0
couldnt start x server on card 1

Drop to runlevel 3 by typing as root init 3
then try commands again.
What is the output of lspci -v

the output of lspci -v related to graphics controller is as follows

00:02.0 VGA compatible controller: Intel Corporation Mobile Integrated Graphics controller (rev 03)(prog-if 00[VGA})
subsystem: Hewlett-Packard Company unknown device 30d9
Flags: bus master,fast devsel,latency 0, IRQ 11
.
.
I/O ports at 30b0

00:02.1 Display controller: Intel Corporation Mobile Integrated Graphics Controller (rev 03)
subsystem: Hewlett-Packard Company unknown device 30d9
Flags: bus master,fast devsel,latency 0

try X -configure as root in the root directory
then type X and get it to use the new xorg.conf in /root