ethernet 2

hi, i just bought an inspiron 3650 i5, nvidia. though i can surf the net using YES GO dongle, it sometimes gives error messages or page not found. when i troubleshoot the network adapter 'ethernet 2' it gave error "ethernet 2 doesn't have a valid ip configuration". i have try to change the ip address, gateway, dns, etc but it still the same. i also follow blog from the web to deal with this problem but still fail. please advise.