There seems to be a problem getting some codecs for windows 10 (and probably 11) there was a time when Canon said they would not make them available, though they are not the only source.
I found an answer that is quicker and easier than using the windows file browser.
Download IrfanView, then go to options and settings, and set the external editing programmes (you can have three, haven't tried to see if I can add more)
Close IrfanView and open IrfanView Thumbnails.
It is very quick to show previews, and I set the preview size to 800X800 which gives me a very reasonable size preview.
If you want to edit one of them, just right click, open with external programme, and select the programme you want to edit with.
Very quick, easy, and the previews are a good size to see.
You also have the option of using IrfanView for quick jpeg adjustments, resizing etc, which is also very quick and convenient.
Even if the codecs were easy to find, I don't think I would bother now.