Won't recognize router

I am totally frustrated with our wireless network in our home. Perhaps you can point me in the right direction. A few weeks ago, our wireless network stopped functioning in our home. The wireless connection on our laptop continued but the desktop (which is not wireless, but hardwired to the router) could not make an internet connection. Since then, I deleted Network Magic and tried to reinstall our D Link wireless router. ((Model WBR-2310 Version A1). Both computers are running Windows XP. I insert the D Link Quick Router Setup Wizard CD and here's what happens:

Yes -- Network adapter is enabled!!
Yes -- Internet connection is OK
Then I install all cables etc in the order on the CD instructions. (Yes, I have tried new cables)
When I get to the final step I have:
#1 Yes -- Network Available
#2 Yes -- Network restarted
#3 Verifying firmware --- UH OH! error 112; Incorrect router.
How can it be an incorrect router when I am using a D Link router and the D Link installation CD? At this point then, even the hardwired desktop has no internet connection and I have to unplug everything and bypass the router to get internet back on my desktop. I took the router to the school where I teach and they hooked it up and the router seems to be working OK. What do you suggest?