will a uATX motherboard fit in an ATX case ?

Solution
Standoffs come with the case, not motherboards. Yes, use the old ones, but you may have to re-position them to different holes if your new motherboard is a different size than the old one. And don't leave extra ones in the bottom of the case that don't match up to mounting holes in your new motherboard, they could cause electrical shorts.
Standoffs come with the case, not motherboards. Yes, use the old ones, but you may have to re-position them to different holes if your new motherboard is a different size than the old one. And don't leave extra ones in the bottom of the case that don't match up to mounting holes in your new motherboard, they could cause electrical shorts.
 
Solution