Hi, my first post here. First of all let me introduce my specs to clarify the problem. q6600-2.4ghz 8800ultra 2gb corsair ddr2 (800) ADDED 2gb more of the same kind, a total of 4gb. IP35-pro mobo Windows Vista 64 bit Home premium My Usual gaming experience is like this: I get the normal desktop crash fussing about the display drivers or the familiar BSOD after playing games like ArmA, Coh, bioshock, and World in Conflict. But today I bought an extra pair of ram since vista was hauling 1gb itself leaving me with 1gb to spare with all my applications I thought more ram was needed. So I boot my rig for the first time on 4gb ram, everything seems normal and vista detects the presence of 4gb so far so good. I go and try out ArmA and the screen freezes in black for about 2-3 minutes. Then I see the ingame menu stuttering with badly rendered background scenario, it was a mess. Ok, what the hell. Next I go play World in Conflict, the menu loads fine but when entereing a game it stutters awfully like ArmA forcing me to get out. What I did to change this situation was to remove 1 of the 4 sticks of ram and boot again this time on 3gb Now it looks like this: Slot 1 ======== 1gb ram Slot 2 ======== 1gb ram slot 3 ======== 1gb ram slot 4 ======== EMPTY So I boot up to vista and check to see if the 3gbs of ram is there and I proceed to ArmA just to see if I get different results. Well what do you know, ArmA loads perfectly fine, I play for about half an hour. Same positive results with world in conflict. I shut down, remove the ram from the 3rd slot and insert the other ram in slot 4. I boot up, check my status and I ran the same games fine. This was to prove that I didn't have a bad stick. I narrowed down my problem to the point where my games wont want to run or hardly run when all ram slots are used up. I don't know what might be causing this issue but its certainly odd, I can only point out that Dual Channel might be interfering with the 8800's tendency to do what it wants with the ram. What should I do, what can I do to fix this issue?