It will depend on if your windows license is configured to your specific mobo or not.
Typically you wouldnt have to reinstall windows as changing a mobo dont change anything on your storage drive, however you may have to re-activate your windows using your windows account because some windows licenses are attached to the hardware inside of the PC. But you can only do this if your current license is connected to your Microsoft account. You will use that license for your new activation. So I would make sure your license is connected to your MS account or you may have to buy a new key. They do this so you cant just buy 1 copy for multiple pcs.
But as far having to re-install, I highly doubt it.