Well can you post your entire computer stats cuz I too have a 3.2 gb processor but with 2 gb of dual channel dds ram and a 256 Raedon Xctacy graphics card. All of my HDRI renders, like the screwdrivers one I have posted in the Finished Work section take less then about 30 mins to render. The screwdriver took 3 minutes to render, batch, from the command line. It might help you to render stuff as batch renders, from the command line. Look into it. It will help.
Anyway, post the scene file too, I'll try to see what is taking up all of your RAM so that your comp crashes. Hope this helps ya.
ChEeRs,
,MaTt