As my computer was taken to the computer shop for checking, meanwhile I found out that Windows 7 's Media Player does not support 4K UHD videos. This explained why both my computers won't play my new 4K UHD videos taken from my new 4K camera, and cell phone that I had just re-adjusted the movie setting to 4K.
As I was hoping to find a program that could help solve this problem. But today I was told by the shop something different. I was told "nothing will help" because "it's my computer". I was told it's the processor of my computer that is not capable of processing such large video files. They added the VLC player program to my computer but it only showed the image but wouldn't play. They said they played them on other computers but it worked. They mentioned "video card" problem - I forgot what they said about it,probably something that I don't understand. They said nothing can be done; no updates can help. They said the only way to solve is to buy a Window 10.
I got the computer back, and tried to open and play the videos with my Photoshop CS6. It played but very choppy.
I will not the option of converting the videos to a lower resolution so I can play it. I especially need UHD resolution to view detailed colors of the videos so I can selectively make still images.
I do not know if there is anything at all that will help in order to avoid purchase two new computers. My Windows 7's work just fine if not for this problem.