The one I clicked on so its blue is an example of quite a few pictures on my HDD that are appearing like this. I CAN click and have them open but before I click they appear as this and I can't see what the picture really is.
You might try deleting and rebuilding your thumbnail cache. It sounds like the actual files are okay, just the thumbs are screwed up.
I know this is 7 but.... http://www.askvg.com/fix-windows-explorer-doesnt-show-thumbnail-previews-in-windows-vista-and-7/ or for 8 http://www.winability.com/how-to-erase-icon-thumbnail-cache-windows-8/