Cannot connect via cable modem

New computer - Dell Inspiron 15R laptop. Windows-7 home premium 64-bit.
Trying to access internet. 7 gives connection option of Broadband where ISP requires ID and Password. However, my ISP does not require this info to log on....its just "plug-n-play" I have run every test and diagnostic that I can find and the only prob I can find is something to do with the DNS, but have no way to fix the problem. The connection is Cable Modem, via LAN wire. One of the diagnostics recognizes my ISP, but still won't let me connect. Any suggestions will be greatly appreciated.


Microsoft MVP
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Have you set your connection to automatically obtain both IP address and DNS address?


Fantastic Member
Don't forget that with a new PC if there is no router you need to reset the modem to pick up the new MAC address. If you also have phone service with your ISP modem pulling the plug will not work you must use a paper clip to push the reset button on the back of the modem due to the battery backup.

Have you set your connection to automatically obtain both IP address and DNS address?
Not exactly sure how to do this in 7. I have set up maybe 10-12 other computers with this modem and connection, under the 98 and XP systems with zero issues. It has always been a "plug-n-play" situation.


Network and Sharing Center --> Change adapter settings --> IpV4,

IP address and DNS address -- set "automatically obtain"
IP address and DNS address -- enter these data manually in the cable modem setup.

Your internet provider and the modem manual will give you more precise instructions.

Ok, will give it a try. THANKS!

Ok, I set the IPv4 to obtain IP and DNS automatically. Rebooted both the computer and the modem. IPv4 recognizes the DNS addresses and the IP, ( and even the IP address, but still will not allow an internet connection. (The addresses it recognizes are identical to the ones used by the computer I am sending this with.) I ran the Troubleshoot ap and I keep getting the same "DNS Server" error. ???


Noob Whisperer
Can you advise as to how exactly you are connecting to the internet;
Something like
Computer to Router (Linksys, D-Link, Netgear, etc.) if you are not using a router please advise.
Router to ISP provided device ( if no router in place, then what type of device is your ISP providing and does it support multiple connections via multiple ports on the back of the device)
Try opening a command prompt and typing
ipconfig /release
and then
ipconfig /renew

Connection: Computer connected directly to Linksys BEFCMU10 ver3 cable modem via Ethernet cable. I have owned this modem for about 5 years. Supports both Ethernet and USB connections, but Win7 lacks the necessary USB drivers for this device and I have not been able to locate them online. I will try the command prompts you suggested.


Noob Whisperer
As member helpifIcan mentioned above, with this type of device (single ethernet connection) you cannot just unplug one computer and plug in another. Your ISP has associated your IP address that they give you with a particular MAC address (the one that is presently connected to the modem), to get it to work you will need to shut down the computer and the Linksys (remove power for approximately two minutes), then power back up the Linksys and fire up the computer. That should do it, unless Cox Net has additional measures in place like incredibly long DHCP lease times.
You might want to think about adding a router that will support multiple simultaneous connections since it sounds like you now have two computers.

Well, I would add a router but I am only going to have the laptop until mid May, when I take it to my Dad - I bought it and had it sent here so I could get it set up for him. (he will be on a dial-up connection and cable is MUCH faster). As previously stated, I have set up quite a few computers using the same modem and it has always been a Plug-N-Play situation. I will try powering down and leaving that way for a while, then bringing back up as you suggested. My ISP's lease times are generally 24hr at a time.


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