Actually many socket 1366 desktop botherboards support 6x4gb dimms for a total of 24gb ram. If you take 24Gb and remove 6gb (for WoW and OS) you are still left with 18gb space. Wow should fit onto this, at least if you clean/delete cinematics and screenshots. I have not tested this at all and dont want to contradict you but it surprises me that it did not work, are you sure you did everything right?