Hello, I recently set up an old desktop (Windows XP) so I could have basic internet browsing in one spot, but I can't get internet to it. It used to have a wireless card in it, but I gave that away to somebody. I can't run an ethernet cable to it, because I don't have any free spots left on my main router. What I want to do is pull out my old router and use it to connect my desktop to the network. My main router is a Dlink DIR-655, and it's plugged into my main desktop (Windows 7), two game consoles, and my PVR. The old router is a WBR-1310, and it is pretty basic. I do remember once using it to make a second network by plugging it into my main router, then I figured out that my 655 can make a second network by itself. I just want to make the 1310 wirelessly take internet from my main router, then put it into my other desktop with ethernet. I don't want it to make another network, or extend my range, or any of that stuff.
I don't think you can easily turn a wireless router into a wireless adapter.
With some models you can get one router to talk to another wirelessly (providing both support WDS and are preferably of the same brand) and I guess you could then connect the second one to the computer by ethernet cable.
The normal use of a wireless connection between two routers is to extend the wireless signal.
Either called "client mode" (as PsychoTeddy said) or "bridge mode". Many alternate router firmwares support bridge mode, but unfortunately, none I know of support the DIR-655. Alternatively, I think you can also stand-alone bridges, but they usually cost so much, you might as well just buy another wireless card or USB adapter, since they sell for 20-30$ now.