I've just upgraded my computer from a DDR2 2x2GB+ASUS M2N32+AMD 5200+ to 2x2GB DDR3(!)+ ASUS P7P55D PRO+Core i5 750. It's the same Win7 x64 ultimate on both configs, but now at system info it says: 4,00GB RAM (1,99 usable). What is with the other 2?? In my old PC it had access to the full 4GB. The modules are brand new and working, I checked them with memtest86, only the windows can't use them. Please help!!!!