I followed the instructions in the Users guide provided with Mathematica-Root. (http://library.wolfram.com/infocenter/Articles/7793/) The first part was successful i.e. I was able to I am not able to load the example.
Import["cernstaff.root",{"ROOT", "Keys"}]
Import::format: Cannot import data as ROOT. >>
I don't know how to proceed from here. Help appreciated.