Windows 10: I cant anymore open mp4 files that I have downloaded to my Windows 11 computer.

I cant anymore open most mp4 files that I have downloaded to my Windows 11 computer, some few I can but dont understand why not all. Strange also that I can open the videos when they sit in google Fotos, but when I download them I cant open them anymore. I get the message .........need the Codec-Pack "HEVC-Videoerweiterung".. but they are normal mp4 videos. mp4 video files taken and downloaded to my old computer Windows 7 and then transferred to my new computer can be opened although taken with the same mobile/camera.

:)

 

Why can't I open mp4 files anymore?

Hello, how are you?

This is happening because, for some reason, an incorrect program was linked to the mp4 extension, so clicking to open it will not work, only opening it will work, as mentioned.

You must change Windows Media Player as the default program to play mp4 video extensions by following the procedure below or through Windows settings.

1. Right-click on an mp4 video and select Properties;

2. In "Open with:" it will show the incorrectly associated program, click on the Change button just ahead;

3. Select Windows Media Player from the list and click Ok.

This will cause the mp4 files to be associated with Windows Media Player and trying to open them will work correctly, test after that please.

 

MP4 Personal Video files lag after August 2016 update (windows 10)

Hi Nicki,

Do not worry we will help you with this issue.

Try few of the troubleshooting steps below and check if it helps.

Step 1: I suggest you to run Video playback troubleshooter and check

• Press Windows key from the keyboard, type
  Troubleshooting and select it.
• Click on view all option on the upper left corner of
  Troubleshooting window.
• Select the Video playback options from the list.
  
• Click Next to run the troubleshooter.

Step 2: I suggest you to copy the files from your computer to another working computer and check if you are able to access them.

This will let us know if the issue is with specific files types on your computer.

Hope it helps. Update of the status of accessing MP4 Personal Video files for further assistance.

Thank you.

 

0xc00d36c4 problem when I read file in mp4 ?

Hi Gilles,

Error 0xc00d36c4 could occur if the video file is unsupported by the media player.

We suggest that you try the solutions provided by Ramesh.Kumar on this
link.

If the solutions provided on the link didn't work, please answer the questions below:

• From where did you downloaded these files?
• Is the issue specific with .mp4 files only?
• Have you tried playing/opening other .mp4 files and check if the issue also persists?
• Where you able to play these files before? If yes, did you make any recent changes on the computer prior to this issue?
• What video player are you using?

We will wait for your reply.