The Nintendo Wii comes with a sensor bar which plugs into the back of the unit to assist with the controller's motion sensing. Its main use is to perform pointing tasks, such as moving around an onscreen cursor. It is also used for depth operations that allow for the controller to sense a somewhat 3D environment. There can be issues with the sensor bar. For example, the onscreen cursor in some games is slightly off from where you're directly aiming. These issues can be fixed with a few edits in the settings of the Wii.

Here are a few tips to guide you to a near-perfect sensor bar setup:

Make sure that the sensor bar settings on the Wii match its placement on your TV.
Under the Wii Settings (the little Wii icon that is on the bottom left corner of the Wii menu), go to "Sensor Bar" and select "Position." From here, you may choose where your sensor bar will be– above or below the TV. The sensor bar only functions from 3 to 8 feet away from the Wiimote. Under "Sensor Bar" in the Wii settings, select "Sensitivity" and adjust between the five levels. To decide which level of sensitivity is right for your playing distance, point the Wiimote at the sensor bar and wait until there are only two dots visible on the screen. Suggestion – a higher level of sensitivity is for a further distance from the sensor bar.

You may calibrate the Wiimotes at any time by pressing the "Synchro" button under the front flap of the Wii, then pressing the red button under the battery flap of the Wiimote. Be sure to only do this with one Wiimote at a time, though, or else problems with calibrating may occur. The Wiimote's pointer function works off infrared lights, so nearby objects which output infrared signals, such as burning candles, may make the cursor "jumpy" onscreen if the interference is too close to the sensor bar.

So, if you have acquired a Wii and are having some pointing difficulties, following these steps should help out with the functionality of the Wiimote. Good luck, and have fun!