Of course it affects networking. Unless you have a separate add in network card, the networking controller is a part of the motherboard, so changing motherboards is going to affect that. You need to do two things.
One, download and install the latest bios version for your motherboard if you don't already have the latest version installed, and you will need to check that as there have been many recent bios updates and releases this past two weeks.
Two, download all the relevant drivers for the chipset, audio, networking and storage controllers from your motherboard's product page, and install them. I'd bet that if you haven't downloaded the network adapter drivers from your motherboard's product page, that is probably all you need to do, plus of course installing them.
What is the model number AND revision number of your motherboard?