you will need to have a wireless card in the desktop pc so that it can get the signal from your wireless router, with out that there is no way it can receive the signal, which is why you are having to plug it in.
There are cards you mount into the back of your pc or ones that can plug into a usb port, not terribly expensive and relatively easy to install.
I gave you some info on your router set up on the other thread.

here is how easy it is to install a card in the pc
Installing a PCI WiFi card in a desktop computer
you may have one already?
How to determine if you already have a wireless network adapter
that link also has instruction on how to use and install the various types of cards.

OK, I understand now. We do have an "ethernet" card but not a wireless card. Looks like about another $40.00 at Best Buy.

Just two more questions and I'll stop- promise!!

Is the card that gets installed by opening the computer superior to the USB version?

And, since the computer already has an ethernet card, would it be possible to connect the router to the ethernet card of the computer and then use the wireless feature for the laptop? (I probably won't try to do this even if it's possible, but I'm curious.)

Thanks once again,

Mark

Internal wireless network cards typically have a fairly large external antenna. That should give you better reception than a USB adapter where the antenna is limited by the size of the device (although there are USB devices with external antennas as well).

You might want to try Newegg. They have plenty of adapters well under $40 and reviews so you can make an informed decision.

Certainly something I personally don't follow (full disclosure!) but for some folks I recommend keeping with the same mfr for for both items because then only one tech support call is made - to one supplier - and they cannot offload the issue on the other mfr's product. Not something in stone for sure, just an observation.

Yes you absolutely can still connect the pc by use of the ethernet cable from the router and use the laptop wirelessly, that is how most usually do it since the desktop stays put. Mine is that way I have my router and cable modem on the end of my desk so easy access from there to my desktop computers so they are all connected by wire, my netbook and laptop are wireless, but even they can be connected by the ethernet cable should you need to. Before I had my wireless router I had a 25ft ethernet cable that ran from my desk on the baseboard to my recliner where I use my netbook.

I buy a lot of my electronics from newegg and they do offer good prices and quick shipping. I also use buy.com quite a bit. You may want to check some of those in comparison to your local store. Also if you have a walmart check there they usually carry these kinds of items and for less. I got my wireless linksys router there.

On the usb cards some come with a cord on them so the usb device can be moved around some on the desk which will help with reception sometimes.

feel free to ask all you need we will try to answer.
I too prefer to buy the same brands when possible it just helps sometimes for compatibility issues.

The quality of help here is wonderful, and the good nature that goes with it is a delight. You've all been great.

We are looking at some more options, and may spend more than we had originally planned, but that's usually the case anyway! Better to spend enough money to be pleased than to cheap it out and live with disappointment.

Thanks again to you all. And yes, I don't doubt I'll have more questions!
Mark