Hi thiyagarajancs, welcome to LQ forums.
@rkski: I had 1-2 instances where GUI installation is not possible. It happens sometimes, do not know why.
@thiyagarajancs: Are you installing 5.3 or 5.4? Can you try other version from one you used?
Please post that internal error that shows when you run startx. Log of the error should be in /var/log/Xorg.0.log.
Pleas post it at http://pastebin.com/
and give us the link so we can look what is happening.