My motherboard is an Asus P5LD2 SE/C, and I'm using 32-bit Windows XP Home. I currently have 2x512MB, and want to add 2x1GB for a total of 3GB, only I was told that this wasn't possible for some reason. The exact words were: "You can only add RAM in two (ie. 2x1GB or 4x1GB or 4x512MB)."