It is possible that your computer is not playing videos and movies due to one or more of the following reasons:

1. Update your computer’s operating system and software
2. Ensure your audio driver is updated and properly working
3. Check your internet connection. A slow or weak Wi-Fi connection may be causing the issue
4. Enable hardware acceleration
5. Clean or reset the browser
6. Check if the video format is supported
7. Run your computer as an Administrator
8. Restore previous settings
9. Try restarting your computer