ASUS P3C2000 won’t recognize ram

Running NT 4.0, tried filling all slots with pc100, only 2 slots get recognized. I tried all combinations of slots and still only 2 get recognized. I reset the bios and added /maxmem:512 to boot.ini and it still won’t work. I dropped the same memorysticks in asus P2B and it worked fine. How can I go about getting the memory to work with my P3C2000 board? Thanks.