Instructions
Wii Shop Channel
Click on the "Wii Shop Channel" icon on the Wii main menu and click "Start."
Press "Start Shopping" on the opening screen.
Click "Wii Channels" to look through available channels. These offer new functionality such as a Web browser and Mii showcase. Click on any channel to view details.
Press "Download" and pick "Wii Console Memory" to save the channel to the internal memory. Confirm by pressing "OK." Wait while the channel downloads.
Back out to the main Wii Shop Channel window with the "B" button. Click "New WiiWare Demos" to view a list of free game demos. Nintendo changes available demos weekly. Select any demo to read more about it.
Press "Download" and select a download location: "Wii Console Memory" or "SD Card." Push the "OK" button to begin the download.
Nintendo Channel
Click on "Nintendo Channel" from the system menu and press "Start." If your system doesn't have the channel, download it from the Wii Shop Channel.
Press the left and right arrow keys to scroll through available videos. Press "A" to view the selected video.
Click on "DS Download Service" to view a list of Nintendo DS demos. Choose any item to prepare it for transfer.
Turn on your Nintendo DS and tap "DS Download Play" on the handheld.
Tap on the name of the download appearing on your DS and press "Yes." The demo will run on the DS automatically when the download finishes.