In a situation like this, try "never to let go both ends."
As far as possible you should make every sort of backup you might need before you do the motherboard swop.
Take meticulous care to get all the connections right, perhaps leave one or two peripherals unconnected for the first switch on, and be ready for all sorts of error messages or weird display.
The CD that came with the motherboard should clear most anomalies. There's no hard law that says you must re-install, just as there is no guarantee it will be snag free.
I have got away with a replacement Mobo and CPU for daughter and her schoolchildren when the Mobo failed, but that computer was not a screaming, ambitious, cutting edge tech. The humbler one needed almost no tweaking.