well im running 2x512 ram in my computer with no program but when i got the another 2x512 ram i put in my computer the total is 4x512 = 2ig of ram cant load. i get a long beep and keep restarting and my screen llooks black. i can put 1.5 gig of ram but when i put 2x512 cant boot. is the mobo is not leting me put 4x512 only 1.5 = 3x512. plz help me.