Redhat Enterprise 5.6 Kernel

It is hard to be the Newbie on the block!

I have a Redhat Enterprise 5.6 server. I have to use 5.6 because the Software that runs on it requires that version. I recently upgraded the Memory from 32GB to 96GB and the change in memory is not recognized by Redhat even though when I look up 5.6 it is supposed to be to support up to 1TB. Then I find out since I have a XEN kernel 2.6ish that memory above 32GB will not be recognized. From what I understand I only need the XEN kernel if I am running a virtual machine which I am not and I am not sure why I have the XEN kernel.

The server is used for single application with a sql database. What can I do to utilized the additional memory?

Do I change the kernel? Which kernel? how?
or
Can I allocate the memory to a VM that will only get utilized by that application?