Cannot play .mp4 videos with the default video player

I downloaded some .mp4 videos on my PC and I want play them on my Samsung Galaxy Ace 2.

Despite the .mp4 videos can be played in my PC¹ (with no problem), in my device (using the predefined video media player) the video cannot be played.

This screenshot shows the videos that my device cannot play them:

Only the video (pointed with the green arrow) - which is the default video that my device has can be played.

When I select any of the other videos, the device says: "Content not supported":

Each time I send the video (via cable from the PC to the device), it will show two options:

Do you wish convert (insert_video_name_here.mp4) before copy it to the device?

• Yes, convert and copy (recommended).


• No, just copy (File will copy, but it might be possible it cannot play in the device).

No matter which option I select, the video is not playable.

This is the information about the predefined app:

I was reading this answer and this one too about similar problems, but what I understand is due the resolution of the video, but I have no idea what can I do for play these videos in my device (despite those videos are .mp4 or .wmv files "the same as the predefined video - pointed with the green arrow in a previous screenshot").

I really don't want download another app and play the videos with them, hence I ask:

How can be played those videos wth the predefined app?

¹ Windows 7 Professional 32 bits. Using Google Chrome "as video player" and the Windows Media Player.

PS: I also read about software which can convert videos for device-compatibility, but I'm not sure if those are free-malware applications.