Re: End of turn ctd
well your PC is powerful enough - though multi-cores are not really relevant and memory over 4MB is not addressable :wink: I haven't downloaded your file yet but end of turn CTD's are usually caused by the re-inforcement bug, doing something before the system has finished updating.
Turning down the graphics settings, making sure anti-aliasing is off and checking your drivers are all worth checking. Any battles? in which case you could try auto_win as a way of getting past them. I'll take a look at the preferences later.