My Dell Inspiron with Windows 7 will initially successfully connect to the internet but then after a while of us the connection will stop. I get an "IP address has disappeared..." message in the security log and the connection does not return. I usually have the reset one or more of the computer, wireless router, and/or broadband modem to get it back. I have COX service. CISCO DPQ3212 modem, NETGEAR WNDR4500 wireless router. Laptop has Atheros ethernet adapter and Dell Wireless adapter with up to date drivers. HELP!