My english is bad, am in learning process so sorry for mistakes in grammar. I read Digit magazine since i loves games in computers. Magazine advises me to buy 8800GTX for smooth gameplay and i buying 2 set of 8800GTX from xfx called ddr3 xxx version. when i come back home to play i remove 7800GTX also from xfx company and now putting 2 new 8800gtx with the SLi my computer does not start. i take my brothers screen called dell 30ultra shape wscreen cause he not use it, and still not computer starting. before i using samsung 17 lcd. i asked my brother who is back home for the problem he tells me that i have check my smpt or smpm so i check and nothing wrong with it. what could be the problem? i put all the wires to the 8800gtx which is having 2 points to put power. if i take out one card then computer starts with both no start. i also buy vista ultimate but i will give it back cause of problem. please help i wait thanks