thankyou, ghonma!
the  /3GB switch allowed me to finish a scene that had proved unrenderable previously ( i have 3Gb of physical ram installed )
on advice from a very well paid and knowledgeable IT consultant, i nervously edited my .boot.ini on both machines, to full success.

the reason for the HU was that due to something unforseen, this action resulted in a boot up failure for my friend.
as i stated before, we subsequently found out that the Intel Centrino CPU is an oddity in that it will throw a fit if you use the /3GB switch.

of course the /3GB switch has no effect if the app you are using is not itself, ' large address aware'

as stated in the Microsoft document, the /3GB switch has no useful effect in a 64bit OS ( windows), in fact is detrimental to performance.