An issue with my cable connection(drivers?)

There was an issue with my PC (it would freeze when logging in) that forced me to completely reinstall windows. however, now i cannot connect to the internet, i dont know why. My PC tells me that my network adapter is not working. Device manager displays a error symbol (the yellow triangle with an exclamation mark on it) on three things. Under the category network adapters, it has an error for the realtek ethernet. Under another category called other devices, there is an error msg for my SM Bus controller and an unknown device. Does anyone know what to do?