For Rock Band and Guitar Hero on PlayStation 3 and Xbox 360, the guitar peripherals are interchangeable. You can use Rock Band guitars on either system or Guitar Hero guitars on either system. With the Wii system, you can only use Rock Band guitars with Rock Band games on the Wii, but you can use Guitar Hero guitars with Rock Band games on the Wii. The issue probably lies in the fact that Guitar Hero guitars use the Wii remote to connect wirelessly, while Rock Band guitars have built-in wireless connectivity with the Wii. Thankfully, neither installation is complicated.
Turn on the Wii with the power button on the system.
Press the sync button under the SD card cover on the system. This is located on the front of the system between the "Eject" and "Reset" buttons.
Remove the battery cover from the Wii remote and press the small sync button there. The Wii remote is now synched to the Wii system.
Remove the Wii remote cover from the guitar. It is the largest cover on the peripheral.
Attach the plug from the guitar to the bottom of the Wii remote.
Set the Wii remote into the opening of the guitar and replace the cover. You should now be able to use the guitar with the game.
Place two AA batteries into the back of the guitar.
Use the Wii remote to enter the game. The guitar will not sync on the Wii home screen.
Plug in the USB adaptor to one of the USB ports on the back of the Wii.
Press the sync button on the adaptor.
Press the sync button on the guitar. The light will glow solid blue when the sync is successful.