To use the Wii Remote with a Wii or Wii U game console, it must first be synced to the console. This might come in handy if your friends bring their Wii remotes. You can also sync the Wii Remote with your computer for use with the Dolphin Emulator.
Steps
Method 1 of 3: Syncing with Wii

Step 1. Turn on the Wii and make sure no game is running on the console

Step 2. Remove the back cover from the Wii Remote

Step 3. Open the SD card cover on the front of the Wii
If you have a Wii Mini, the sync button is on the left side of the console next to the battery compartment.

Step 4. Press and release the sync button on the back of the Wii Remote
This button is located below the battery compartment. The LEDs on the Wii Remote will start blinking.

Step 5. Quickly press and release the sync button on the Wii while the lights on the Wii Remote are flashing

Step 6. Wait until the LEDs on the remote stop blinking
When this happens, the remote will be synchronized with the set-top box.
Troubleshooting

Step 1. Make sure the game is not running on your console
Otherwise, you will not be able to synchronize the remote control with the set-top box. Go to the Wii Main Menu before syncing.
If syncing fails, remove all game discs from the console

Step 2. Insert new AA batteries into the Wii Remote
Synchronization may be failing due to discharged batteries. Try replacing the batteries and re-syncing the remote to the console.

Step 3. Disconnect the power cable from the back of the Wii and wait for about 20 seconds
Then reconnect the cable and turn on the console. This will reboot the Wii, which may resolve the issue.

Step 4. Make sure the Sensor Bar is installed above or below the TV
The Sensor Bar is responsible for how the Wii Remote points to items on the screen. This bar only works best when it is above or below the TV.

Step 5. Reboot the Wii Remote
To do this, remove the batteries, wait one minute, and then reinsert the batteries. Now try syncing your remote and console.
Method 2 of 3: Syncing with Wii U

Step 1. Turn on Wii U and go to the main menu
If you try to start Wii Mode without syncing with the Wii Remote, you will be prompted to do so

Step 2. Press and hold the sync button on the front of the Wii U until the sync screen appears

Step 3. Remove the back cover from the Wii Remote

Step 4. Press the sync button on the back of the Wii Remote
This button is located below the battery compartment. The LEDs on the Wii Remote will flash and then light up to indicate a stable connection.
Troubleshooting

Step 1. Make sure the game is not running on your console
Otherwise, you will not be able to synchronize the remote control with the set-top box. Go to the Wii Main Menu before syncing.

Step 2. Insert new AA batteries into the Wii Remote
Synchronization may be failing due to discharged batteries. Try replacing the batteries and re-syncing the remote to the console.

Step 3. Make sure the Sensor Bar is installed above or below the TV
The Sensor Bar is responsible for how the Wii Remote points to items on the screen. This bar only works best when it is above or below the TV.
Method 3 of 3: Synchronizing with a Windows computer

Step 1. Use a USB Bluetooth adapter if your computer does not have a built-in Bluetooth module
The Wii remote can be connected to a computer via Bluetooth, allowing it to be used with Dolphin emulator or other software.
If you restart your computer, you will have to re-sync the remote with your computer

Step 2. Right-click on the Bluetooth icon on the taskbar and select "Add Device" from the menu

Step 3. Press the "1" and "2" buttons simultaneously on the Wii Remote so that the lights start to flash

Step 4. Select "Nintendo RVL-CNT-01" in the device list, and then click Next

Step 5. Select “Pairing without code” and click Next

Step 6. Wait for the Wii Remote to connect to your computer

Step 7. Launch Dolphin and click the Wiimote button

Step 8. Select "Real Wiimote" from the "Input source" menu
This will allow you to use the Wii Remote while playing games in the emulator.

Step 9. Find a sensor bar for your computer
Use a battery-powered sensor bar or make your own.
Troubleshooting

Step 1. Close Dolphin before syncing your remote to your computer
Otherwise, the controller selection menu may not open. Close Dolphin, unplug the Wii Remote (right-click on it in the Bluetooth menu and select “Uninstall Device”), then try syncing the remote to your computer.