As a precaution I'd try a known good CPU before you decide the mobo's duff. If that fails, then I think you're right.
If you get an identical mobo you can get away with simply swapping everything over.
Failing that a repair install of Windows will allow it to run on the new mobo bundle without losing your stuff or requiring re-activation.
If, like me, you need to go the reinstall route you will have to activate Windows. Mine's XP Home OEM and I'd switched to a different mobo so I was expecting it to fail, but it went through OK