I'm trying to upgrade my Ram for my Dell Inspiron 580 i5 650 @ 3.2 GHz. I bought a PNY DDR3 2x4GB 1600,1333MHz Ram. I put in just one and my computer will start up at the Dell logo with the bar at about 25% and will stop. So I put in the old 3x1GB in the other slots and my PC would load the the windows logo and the say it would run into an error and restart. It would continually do this until I turned it off. So I put in both 2x4GB in both in the slots to communicate and it loaded with the Dell logo and just stop. I tried both slots 1 and 3 nothing,2 and 4 nothing.