ISP-Computer mismatch

[reeder2]

I have 2 Acer Aspire One netbooks, running Windows XP, Service Pack 3. AVG Free virus protection.
1.6 GHz, Intel Atom chip. 0.98 GB. I have been able to link both of these Acers tol different secure wireless networks through Cbeyond and ATT & T. I can also connect to any unsecured network I try. However, neither of the Acers is able to use Comcast at my house or at a friend's house. (Yes, I know the passwords). These Acers show an active connection in the icon in the lower right-hand tray, but they cannot find a server, regardless of whether I use Mozilla or Explorer. I have been able to use several other brands of laptop with these same Comcast home networks. So the problem is associated with the Acer-Comcast matchup. I assume it is a modem, router, or NIC problem. The modem is Actiontec and the router is Netgear (at my house, where I am now. I do not know the modem or router at my friend's house). The network adapters are Aetheros (wireless) and Realtek (wired). I cannot connect the Acer through the wall either. I apologize if this is actually a software rather than a hardware problem.

[Geek-9pm]

As for Cbeyond, I have nothing to say.

ATT and Comcast have different setups. I recall that you have to do the setup over again when you switch from one to the other. Maybe I am wrong about that.

The routers used by ATT are different from the on es used by Comcast. Not just the speed and protocol, but the way they verify your account. You need to contact the Comcast support and find out what you are doing wrong.

Is there a reason you need to switch back and forth? If so, you should set it up so the local router does the work, not the laptop.

With Comcast thee is an issue of people trying to 'boot leg' service off of a Comcast cable by splicing into it and using a outer not known to the Comcast server. Of course, that is not what you want, -right?

Comcast has documentation that explains how visitors to a subscriber home can log on to a LAN wireless and get into the Comcast internet.  service.

It is against the terms of use for a subscriber to 'broadcast' his Comcast connection to the entire neighborhood using WI-Fi. Unless you have a contract for that.

[jason2074]

Try Winsock reset/fix http://windowsxp.mvps.org/winsock.htm

[Computer_Commando]

... I cannot connect the Acer through the wall either....

What does this mean?

[reeder2]

@commando:
I cannot connect via a wired connection either (Cat 5 cable, data port in wall).

[Computer_Commando]

If you can't get wired connection, it's definitely the Acer.  Is the Acer set for DHCP?

It's nothing to do with Comcast or the router.  There is a difference in the router setup for cable vs DSL.  Routers connected to cable modems use "Obtain IP Automatically", DSL use "PPPoE".

http://en.wikipedia.org/wiki/Point-to-point_protocol_over_Ethernet

Comcast does not provide or support routers, they provide a modem only, unless you choose to provide you own modem.