If you are building a new desktop PC and planning to use more than 4GB of memory, then you should do some research on the hardware and software first. I had a customer today who was ordering some parts from my computer store to build his new gaming computer. He ordered the ASUS P5K SE motherboard, 4 sticks of DDR667 2GB memory, Windows Vista Home Premium 32Bit version, along with some other hardware. When I saw the ordering list, I could tell that this customer will not be happy with his new system once he built it because he will not be able to utilize all 8GB of memory.

The problem is due to the 32bit operating system. Although the motherboard is capable of supporting up to 8GB of memory, the 32bit operating system can only see up to 4GB of memory. Even for Vista, if it is 32bit version, then you can only use up to 4GB of memory. In some situation, the 32-bit operating system will not be able to recognize the full 4GB because some of the memory addresses are reserved for the system hardware. You will probably see 3.xGB of memory only.

Solution? Switch to a 64-bit operating system, as I have suggested my customer to get Vista Home Premium 64Bit. Also, you need to make sure that the motheboard chipset can support 8GB memory or more. The ASUS P5K SE, using the Intel® P35 chipset, is capable of using 8GB of memory.