4 sticks of ram doesnt work
 

I just bought these 2x512mb OCZ DDR PC-3200 Rev 3 Dual Channel
to add to my current 1 gig (CORSAIR TWINX PRO 1024MB (2x512) 400MHz DDR PC3200 CL2 + LED ) . I put in all four sticks but the system doesnt boot. The two set of ram will work separately but not together. I know know why it doesnt work. Can some one help? Thanks.

specs

Corsair memory is very picky when it comes to running together with different ram. It might be that you cannot run them together at all.

A BIOS update is all I can think of as solution.

Did you try them each paired up in one of the channels each?
Did you check if the maximum numbers of ranks your motherboard supports? (this is maybe more a server issue)
And like rutar mentioned, did you try upgrading your bios?

My mobo is a DFI nf4-sli dr, and the OCZ ram's are in the yellow slots and the cosair in the orange slots, i will try a bios update

1) Clear CMOS 2) Use one module or one pair 3) set to 2T CPC 4) reboot, if works 5) install remaining 2 modules.

4 sticks could only be run with 2T.

how can i clear cmos?

A guess on your mobo is't going to be a jumper.

http://www.dfi.com.tw/Upload/Product...4%20SLI-D1.jpg

The red 2-pin jumper on the right of the battery at the left bottom corner of the board. Move the jumper from current position to the other side to reset. Make sure to put in back to the original position, you are done.