Everlong is totally correct, the I/O panel and the card slots on a BTX board are upside down compared to an ATX mobo, so you would have to reverse the whole back of the tower. In regular practice they are not compatible but I guess it could be do-able on some level, if you had the right tools and a LOT of time to burn, but it would be a CRAZY amount of work. So...call it a 'mod project'?