please look this Blog "Adding ethernet connectivity to a STM32-Nucleo" from Carmine Noviello: https://www.carminenoviello.com/2015/08/28/adding-ethernet-connectivity-stm32-nucleo/this will help you with the W5100
Yes I did both. Actually i reopen the configuration Windows clicking the file with the blue icon( I don't remember the extensión), but after saving with ctrl+S, the IDE did not regenerate the code, I need to press Alt+K to generarte the code again