Here are some step by step instructions to ensure your Wii hardware is setup correctly.
-First make sure any remotes you're using are properly synced. Here's a link to Nintendo's official instructions, they are also located in your Wii System manual.
-Second, make sure your sensor bar is correctly positioned. It must be placed either above or below the TV and centered to the vertical axis of the screen. A clear plastic cradle should have been included with the Wii along with some double sided sticky pads to attach it to vertical surfaces.
-Third, go into the Wii system menu and make sure the system settings for the sensor bar are set to match the position of the bar either above or below the TV.
-Fourth, make sure there is nothing interfering with the sensor bar and the remotes. The bar is actually just two infrared lights and the remote's sensor is an infrared camera, so any source of bright light, especially infrared light can cause problems. Direct sunlight is the most common problem people face but sometimes candles, lamps or string lights near the TV can also create problems.
-Fifth, you should be at least three or four feet away from the TV because the camera in the remote needs to be able to see the sensor bar and the TV for it's auto-calibration to work. If you are too close you will have to point towards the sensor bar in order for the pointer to appear on screen.
-Sixth, ensure the batteries are well charged by pressing the home button. Often when the charge drops below %25 the pointer and motion sensor functions begin to become less accurate. There are some really great 3rd party adapters for Wii remotes that have rechargeable lithium batteries and allow you to simply place the remotes in a dock to recharge. Just ask you local game retailer to show you their charging stands or docks.