I was helping someone copy pictures from their iphone when I noticed the file format was HEIC. It didn't produce any thumbnail image and no program could open it. HEIC files are a picture format introduced by Apple. It stands for High-Efficiency Image Container. Its supposed to give higher quality images than JPG but smaller in size. Windows currently does not have any native support for this file type.
My current system couldn't handle them so I had to go to www.copytrans.net/copytransheic and download and install CopyTrans HEIC for Windows. It's free for personal use. I downloaded and installed it and immediatally the thumbnail became available but only Windows Photo Viewer could open it. My Xnviewer couldn't but IrfanView could, but only after installing CopyTrans HEIC for Windows.
I decided to convert these pictures to JPG using IrfanView - www.irfanview.com
Open up IrfanView and click on File and then Batch Conversion/Rename... in the drop-down menu.
In the top right pane where the files are listed select the files you want to convert. You can choose individual by clicking on a file and then the Add button or my case I'm selecting the Add all button. By the way dragging and dropping from the top to the bottom also works.
Choose your output format on the top left-hand menu. I'm leaving it on JPG-JPG/JPEG Format
Choose your output folder where it says C:\TEMP. Use your browse button to choose your output or save folder.
Then click on the Start Batch button. Now you have a bunch of more manageable photos. Future generations of Windows might have more native support.