hi to all members ,
hello sir, i did try us suggetion but again there is no result i mean there is GUI at the time of boot but when its login screen then from that point on there is no GUI only a black screen with mouce pointer.
i also tried by booting the system in Full multiuser mode (INIT 3) by changing in /etc/inittab
and then tried
$init 5
and no result

and when i tried
$startx
then it gives me Gnome GUI

for woking which is working good with out any problem.Apart from this 1more interesting that now started is at the time of shutdown or reboot the XFC and ACPI daemon fails to shutdown and shows Failed message status.
thanks and regards
Kapil