SOLVED W7 - Onboard NIC disallows USB Wifi adapter to work simulta

I have an HP W7 (Home Premium) PC. I have a wired connection (on-systemboard network interface) to a Belkin 54g router, but the router is not physically connected to the internet (no ethernet cable out to a cable modem/whatever). The router connects several necessary peripherals - mostly wirelessly to the main PC and another W7 PC.) All this stuff worked prior to a move to a new location. There is freely accessible Wifi in range (public library - wherein I could concievably carry the whole PC and use their WiFi with their blessing). I attached a USB Wifi adapter to the PC to avail myself of the free service, but W7 will not allow the Wifi adapter to be seen until I detach the ethernet wire. Then it will allow me to see the available network, and connect. How does W7 (or the system board) look at network? Are they (onboard NIC and USB) mutually exclusive? Do I need a separate ethernet adapter card or a separate USB adapter card to create a different "channel" that would allow the two networks to coexist?

To clarify, are you saying that you are unable to "see" any wireless networks listed while the ethernet cable is plugged in? This doesn't sound right.

Maybe I am confused. Maybe you are trying to say that the internet just simply doesn't work until you unplug the ethernet cable?

If thats the case, it really makes sense. You are unable to have multiple network connections on any computer unless they are configured properly. I can tell you now that your router is not configured, and probably cannot be configured properly to make this work. The router is going to provide IP addresses (via DHCP) to each of the connected devices, and part of that IP information is what's called a gateway address and a DNS address. The gateway address tells your computer, in simple terms, where to find the internet. The DNS address tells the computer who to ask for directions to each website.

Now, throw in your wireless adapter, it now receives a second IP address, with a second gateway address and a second set of DNS addresses. What address do you think your computer is going to use to find the internet? Who knows, that's why you can't have two sets of addresses. Your router, probably being the standard home-based router (pretty cheap, and limited on options) will have no way to manually configure what gateway and DNS information it gives to each connected device. And so, your computer continues to try to connect to the internet through your router which has no internet connection.

There is really only one option to fix this problem. You can manually configure the IP information on your wired connection with a static IP address and subnet, but leave the gateway and DNS addresses blank. This will cause the computer to use the proper gateway and DNS information when you connect the wireless network without interrupting communication to the other devices on your network.

So, go into your network connections, identify your wired network adapter, right click it and click properties. Identify the TCP/IP protocol in the list, select it, and click properties. Put in a static IP address, and subnet mask that matches what is used on your network. And leave the gateway and DNS information blank.

A basic understanding of networking principals makes this a lot easier, but suffice it to say you can't just put in any old numbers and expect it to work. You can use the ipconfig command (at the command prompt) in order to determine what your current IP address and subnet is. You can then use those same numbers and enter them manually in your TCP/IP properties while leaving the gateway and DNS blank.

Now, technically speaking, there are two more things that can go wrong here. One, your wired network, and your wireless network, by chance, could be using the same network addresses (i.e. your wired connection has an IP address that is 192.168.1.x and your wireless connection has an IP address 192.168.1.x) which means its just simply not going to work unless one or the other is reconfigured (reconfigure the router to use 192.168.2.x for instance) to be on a different network. Or, two, your router just might assign the static IP address you chose to another device because you did not use an IP address that was outside the IP addresses allocated in your router's DHCP settings. All these settings can be found in the router's configuration web interface.

If all this sounds confusing, it is, and I'm sorry, but without a bit of basic networking there is no easy way to explain this process to you because it is dependent on understanding the various settings you currently have implemented at your location and is not something I can tell you. I've provided enough terms though so that google should give you a wealth of knowledge and direction.

Then, as if this wasn't enough fun already, you can bridge the connections and allow any other devices on your network to also access the internet through your one computer.

Thanks, Appleoddity. See my resolution reply (next). I got it sorted out over the weekend. G00k

Friends and Fellow Geeks, Thank you for the responses and suggestions. I find that struggling to frame a question that won't take you and me down long side paths and clarifications, actually helps order my thought processes in thinking about solving the problem. Other times, it reminds me of how much there is to know out there, and without good technical support (that's you folks!), I would be adrift at sea. Then someone smacks me on the head with an oar, and and says, Snap Out Of It!, and I proceed to the solution. Ultimately, the solution for me included running an ethernet cable from the non-internet-connected router to the second PC, setting up static IP's for that network, killing the gateway and dns for them, and letting the wireless usb adapters do their thing for the wifi internet access. The brain-fart had been that I was trying to force two networks on one adapter on the second PC - what was I thinking? Some times I need that smack upside the head. Thanks again. G00k

I'm glad to hear you got it sorted out and you actually understood my directions. I was worried this was going to turn into a 20 post thread just to setup this basic connection.