if the motherboard and processor worked fine at the store, what is different at home, ram, power supply, video card? the only thing i would hook up/ attactch would be the ram and video card, and the power supply, if the problem still occurs, it has to be one of them, does your motherboard have on board video? if so did you disable it, may have to boot up with the onboard, disable it, then reboot with the new card in, if youre ram is different then what was used at the store, are you sure you have the right ram, if the ram is ecc, the board may not support it, or some boards dont support double sided chips, i am not sure of your board, there are many sv266 boards, they have a letter like A or AD or M , so i can only speculate. the ones i looked at were dual supportive of ddr and sd ram. you can use one or the other, you can not mix the two.