I recently tried to upgrade the memory in my old Pentium 4 box that has an Essex board. (I do not know Intel's designation for this board, only the box manufacter's. I do know that it was called "Essex," though.) It is supposed to accept up to 2 x 1GB memory. I bought two such PC2100 DIMM DDR non-ECC non-buffered high density, and I got an endpoint error. What was the problem? The amount of memory? The high density? SOme setting in BIOS? I am trying to squeeze life out of this old box, as my family does not have enough boxes to go around. Any advice?