I just upgraded to Win 7 Proffesional 64 bit, I have four 2 Gb Ram sticks A-Data DDR2 800 MHz
And an Asus P5QL Pro motherboard with a P4 D930
I can run with 2x2GB stick NOT in dual chanel mode. If I put one or two more sticks Win will freeze, 3 or 4 GB, It will look as if its trying to load but will take ages an nothing will happen. If I take out the extra memrory and stay with 4 GB the system will start with no problems.
I do not understand the BIOS settings so most of them are set to Auto, default.
I know the memory is not on the Asus list, but that hasn't been a problem with previous Asus Motherboards.
I havent tested the 4 GB in Dual Chanel.
I have updated Win 7 and used the 64 bit chipset drivers from Asus and also the nvidia video drivers.