Add a cover image to the icon - embedded image?

[B.Luedtke]

I am sure this has been asked before, but maybe I don't know the terminology.

I have a fair few books I have downloaded from various places. Below is an image of a few official GamesWorkshop books I have bought. They all have cover images.

However, any PDFs I create just show the generic PDF icon. This test PDF has an image as the first page.

However, this isn't an issue with turning on "Enable PDF thumbnail previews in Windows Explorer". When I enable that I see this:

This is clearly a preview because there are white bars to either side of the blue image.

So how do I set an actual cover image like all those professional books?

[Luke_Jennings]

Here is how you do it on a Mac, not sure how to do it on a PC.

https://support.apple.com/guide/mac-help/create-custom-icons-files-folders-mac-mchlp2313/mac

[B.Luedtke]

Thanks for the reply, but that's not what I mean. I didn't download cover images for every book, they came like that already. Nothing was set custom on my end to see those book covers.

I don't really know how else to put it. PDF files, when they are books that I have bought and downloaded from the vendor, show the book's cover as the file icon. PDF files I create show the generic icon. This is happening while the option to preview PDFs is disabled. I don't want to enable that, there's no reason. I just want to be able to add my own book cover to the PDF so that anyone I give it to can see it.

[Luke_Jennings]

You can add a page to the beginning of the book using Tools> Organize Pages> Insert> From file.

The first page of the file should become the icon seen on the unopened PDF.

If you go to View> Show/Hide> Navigation Panes> Page Thumbnails you should see smaller images of all the pages on the left side of the window, the first thumbnail will be the icon for the PDF.

It might be possible to make a PDF without thumbnails, which could be your issue, if that's the case, try dragging your first page to the thumbnail panel to create a thumbnail, then save.

If you want to add an icon image to the unopened PDF, that is not the first page of the PDF, the link I sent earlier explains how to do this on a Mac, the technique for a PC is probably similar. 

If the icon is working properly in Acrobat & Reader, but not all PDF viewers and browsers, I think you will need to ask your question again and explain which viewer or browser is not showing the desired icon.