how to install inel-graphic driver to centos/rhel 5?

What version of Ubuntu or Fedora is centos/rhel 5 based on?

Hi - I'm afraid RHEL isn't one of our target distributions, and since the graphics stack is fairly
fast moving I suspect any attempt to transplant into an older/slwoer moving distro like RHEL
is doomed to failure.

For what it's worth, the versions of all the software involved are listed on the 01.org release notes
for the graphics stack, so if you can find a repository with suitable updates for RHEL 5 then you
could use that - the grpahics driver itself is the i915 driver from the mainline linux kernel - so if
you install a new enough RHEL kernel you'll get what this installer would have provided.