Hate the thumbnail for your video because it’s either all black or just not what you were looking for? YouTube allows you to choose from 3 thumbnail images created from your video clip. Here’s how to change the thumbnail image for your video:
For my example I am using a copy of Davak’s excellent video from his Wii: Send Photos to Friends recipe.
1. Go to YouTube and login to your account.
2. Select My Account from the menu in the upper-right portion of the page.
3. Go to the Videos section and select My Videos.
4. Find the desired video and click the Edit Video Info button on the right side.
5. You will then be presented with the three thumbnails from the video clip. Select the one you want.
6. Click the Update Video Info button.
Once YouTube makes the update, your video will be represented by the new thumbnail.
Note: YouTube states that it can take up to 6 hours for the change to take effect.