Game Icon to be set from Library

Is there a way to set Game Icon from already loaded pictures in library? I see only options to load it from computer. I now accidently deleted one I used and cannot find it on my computer anymore, so it is quite unconvenient.

At this time, Game Icons are only able to be uploaded from your computer. In your situation, you may wish to save the image in question from  Your Library to your computer* and then reupload the image. (Optionally, you could then delete the original image, replacing it fully on all counts with the newly-uploaded image via drag-and-drop.) *To do so, I recommend right-clicking on the image, copying its URL, and saving the image only after replacing "thumb" within its URL with "original".

Thanks, that did the trick!