OK, I checked the spec for the Asus board and found the c-net review specifically stated that it was a micro-ATX board. My measurement of the existing Acer board convince me that it's also micro-ATX, based on the Wikipedia description of the form factors. It's very annoying that I can't find a spec for the Acer motherboard. The spec for the Acer Aspire M-1610 computer that it's in only gives a measurement for the chassis, which I take to be the inside measurement of what I call the case. I've changed most of the other components inside the case, but this is the first time I've had to consider changing a motherboard, so I don't know much about how the mounting points are located. I'm pretty sure that many of the other motherboards available would NOT fit, because they're too large or too small in one or both dimensions. I'm glad the Asus mobo will work, because according to their web site that's the only board my supplier carries that has Socket 775, and I really don't want to have to change the CPU.