Hey!!!
I also have one of those Digital Music Players.
The Name of the brand is MUSIC NO LIMIT (I did some reasearch on it!). It cannot play MP4 videos even though it says so on the box. Those chinese people love to lie!!!
The videos you watch on it have to be in the .AMV format. (AMV stands for Adavance Media Video)
All you have to do is:
1. Find a program which can convert videos to the AMV format (I recommend AMV Converter Tool but you can just google "AMV Converter" and you will probably find something similar.)
2. Convert the video using the AMV Converter you downloaded.
3. Plug in your MP3,MP4 DIGITAL PLAYER. (My computer, it is windows XP, recognised the player as a removable flash drive)
4. Go to my Computer. You should be able to see an Icon saying removable disk (Probably)
5. Double click on it. Now you can see everything that is in the player.
6. Now copy and paste the video file which you converted in step 2
7. Now unplug the player from the computer. I ecommend using that safely remove thing, just to be on the safe side.
8. Switch on your player (If it is not already on) and the video file should be there!
Hope that helped!!!!!!!!!!!!!!!!
See you all
& hope your little sister likes it!!!