Sys. Specs: dell dimension 4600 Intel P4 2.4 ghz 2x256 mb DDR400 ram(factory from dell) infineon CL3 PC3200 nvidia Geforce 5200 FX I bought two sticks of 512mb DDR ram(PH ddr400 512mb, CL 2.5, MD44-M57JA) On the mother board there are 4 slots for memory, order goes 1 white, 1 black..1 white, 1 black. I know the memory must be in the same color slots to operate properly. The problem is when i boot up...It recognizes the total amount of ram ~1534mb, then i go to setup mode(hit F2) and check the system for the ram, its there. Exuent setup...goes to windows log in screen if im lucky and freezes. I check the error log entry in setup after rebooting and see a POST error(don't laugh behind your screen!...what is POST?). I have entered the memory as follows: 2x256 in white, 2x512mb in blackand reverse, and 2x512 by its self(in that case i turn on the comp and here beep...beep.......beep.beep: nothing happens just more beeps) Can any one give some expert advice on what to do?