My intenet stopped working but it says I have full strength

Ok k so I just got a preowned acer aspire one from the pawnshop today ..when I initially turned it on it was running kind of slow but at least my internet was working and said I needed to update it to windows 8.1 so I did after the reboot it was still acting stupid I then ran norton antivirus and found multiple problems which then I supposedly "fixed" with the program then once again had to reboot after it restarted everything seemed to be working properly except then my internet stopped. It says im connected with full strength but no browsers or apps req. internet work ive done everything uninstalled norton , winsock reset ect...idk what else to do please help.