RAM Issues

I believe the problem is that your mobo can only support 4GB ram max and this may well include your video memory (thats the memory on the card and physical ram reserved for gfx use) which may well total around 1GB limiting your usable ram to around 3GB.

If you look at system in control panel it should say installed ram 4GB usable xxGB

PurpleMonkey said:

So I went out and got Windows 7 Professional and I picked up a 2x2Gb OCZ DDR2 kit. Eager as a kid, I install the ram and go and install Win7. I notice that only 2943Mb of RAM are "installed." When I check the BIOS, is says that 4 Gb of RAM are installed but 1 Gb is "appropriated." My buddy is running the same chip and mobo as me and his setup acknowledges all 4Gb. The differences in our systems are his video card (GTX260 core 215, I run 9600 GT) and the brand of his RAM (Corsair). Otherwise, Intel Pentium D (830 i think? - 3.00Ghz), and Asus P5LD2 Deluxe mobo. Any input would be appreciated.

Right click on task bar, go to task manager, go to performace. What are the memory stats that are shown, in the chart bottom, left.

It is very hard to buy ram when its mix and match.

I didn't read wall-of-text. But I gather you're running mixed RAM and that is always a precarious situation. The newer, high-end systems are delicate enough without adding mixed RAM timings to the system. Pull the varied RAM, try running matched pairs and you will see stability.

Well according to his text,, he is only running 2 x 2G of OCZ ram,,, so not mixed.
I thinkk Pauly is right

According to your screenshot it is seeing all 4 GB