Windows Memory
I ran across an excellent article on Windows memory use today. http://www.gamasutra.com/view/feature/3602/sponsored_feature_ram_vram_and_.php This article covers both the limitations of 32-bit Windows memory models, and the ways to get your applications to work well in x64 Windows. Written primarily for game developers, it's still an excellent read for those who have struggled with understanding why their Windows XP or Vista can't use all of their 4 GB of RAM. Or why they can't have all 8 GB used by Vista 32-bit.
Charlie.