Help with Wii U

Power cycle both your Wii and your router/modem. Try to make sure NOTHING else is connected to your network if at all possible, and keep the wii as close as possible to it. You may simply have an unstable wi-fi connection, and it's dropping your connection periodically. One of my old routers used to do that, but worked fine with Ethernet cables. Sadly the Wii U doesn't have that option and is only wireless.