Why the old version of 4k video download failed to download on my pc?

About the 4K video downloader. You can use Browser Inspector Tools. This is a manual, technical, but very educational method that involves no extra software. It works because your browser temporarily assembles the video from smaller files.

How it works as 4K video downloader on Windows 10/11 computer:

1. Open the YouTube lecture video in your browser (Chrome or Edge work best).

2. Open the Developer Tools (F12 key).

3. Go to the Network tab and filter for media.

4. Start playing the video. You will see a list of files populate. Look for the largest file, which is often the video or audio stream.

5. Right-click on that file and select "Copy > Copy link address."

6. Paste that address into a new tab. You may be able to download the file directly via "Save As." For higher resolutions like 4K, the video and audio are often separate, requiring you to find and download both and then merge them later with a free tool like MKVToolNix.