Try doing a repair. Go to the control panel, open network and internet connections then network connections. Right click on your network and select repair.
We have had 2 computers for many years, we are connected through a Linksys router and all of a sudden, computer #2 cannot connect to the internet...this has been going on and off for the past week, we were on the phone for almost 2 hours last night, 1 (the main) computer is now on line but the second one is not..tech support (?) says its the realtek in the second computer that has to be fixed...thinking of calling an in home repair company..any suggestions from anyone??