Have you tried reseting the router. Or going through cmd and doing a
ipconfig/release
then
ipconfig/renew
You can also shut the modem and router off for a few minutes and then turn them back on to see if it helps.
You can also use device manager to disable the wireless card and reenable to see if it resets the connections and fixs the problem.
Also you can update the routers firmware and the wireless cards driver.
Also you can simpely restart the computer.
Many different things to try.