it must be asking for a specific file format to play those videos or maybe it ask for a video converted with a specific tool
You may be correct. The paltry "User Manual" mentions a "MP4 transference tool that will be provided for free". The player didn't come with any discs so I searched for converter software for Window$. The manual says the player is a PMP -Slide Panel so I used that in the search. I found a site that had some software that claimed to work for this player. Tried to use it with no luck. I got an error message and the program locked up.
I'm not going to mess with trying to play videos on this. I bought it as an MP3 player so that's good enough for me. It has some extras like a calendar, calculator, camera and video recorder that I may use.
For $28 I guess it was worth it. No telling how long it will work though. vc