Windows 7 sometimes causes a problem IN routers. Google and you will see.... it's happened to me a couple times. Rebooting the router fixes it till next time. IF the drivers for your network card are not a problem.
One other problem that shows up in the administrator logs can be traced back to the Wlan service running all the time. Since you use wire.... you don't need this service. The default is set to run all the time.... and every 60 seconds it goes into a refresh state to check for a better connection. If you are a gamer, when it refreshes you can have a short pause... by that time you are killed... so naturally gamers hate it and turn it off. Check my blogs.. probably my last one... I had to use a program to...