Is this your motherboard?
Newegg.com - ASUS Rampage III Formula LGA 1366 Intel X58 SATA 6Gb/s USB 3.0 ATX Intel Motherboard
If it is your mobo then what memory are you currently using? That mobo is a triple channel mobo so you want to use sets of 3, as in, 3GB (3x1GB), 6GB (6x1GB) or (3x2GB), 12GB (6x2GB) or (3x4GB), 24GB (6x4GB).
If you already have 3GB then you can add 3GB (3x1GB) more for a total of 6GB, or you can add 6GB (2x2GB) for a total of 9GB, etc...
Your requesting 1066 DDR3, that's really slow memory, I mean really slow. Most pre-built system come with 1333 DDR3 while most Custom systems come with 1600 DDR3. You should post some screenshots of the CPU tab, Mainboard tab, Memory tab, SPD tab of CPU-Z v.1.58
. On the SPD tab make sure you've selected a slot that has a stick of memory in it.