If you ever got MP4 Files, you'll notice that the MP4 file will not displaying thumbnail as AVI and MPG do. Now we can make the thumbnail visible for MP4 files
1. Create a new empty text file.
2. Copy the following into the text file:
3. Rename the file from .txt to .reg
4. Double-click on the .reg file. You will be asked if you want to import it into your registry. Click yes.