The motherboard is the backbone to a computer, changing it is one of the riskiest things to change if you do not back up your information.

The real thing is changing from chipset to chipset, but each situation is unique. If you are going from one nForce 3 board to another nForce 3 board, I wouldn't be too worried. If you are going from a VIA K8T800 board to an nForce 3 board, I would be worried. I am only talking about Windows corruption here though, not hardware corruption.

It is near impossible to screw up your hardware. If something is not compatible, in most cases, it will not fit. If you have to use excessive force to install the hardware, I'd double check compatibility.