When you open a HEIC picture file for the first time in the default Photos app in Windows 10 version 1803, the Photos app displays “Install additional codecs to work with this file” message along with “Download codecs at Microsoft Store” link.
HEIF and HEVC Media Extensions for Windows 10
Clicking on the “Download codecs at Microsoft Store” link takes you to HEIF and HEVC Media Extensions page in the Store app. You need to install the HEIF and HEVC Media Extension app to be able to view HEIF/HEIC and HEVC media formats on your Windows 10 PC.
As you can see in the picture below, it seems the HEIF and HEVC Media Extensions app is no longer free. Microsoft has started charging a small fee for an app/plugin which should have been part of Windows 10 in the first place!
Apparently, the HEIF and HEVC Media Extensions were available for free some time back.
Luckily, there is a similar HEIF and HEVC Extensions pack (HEIF and HEVC Media Extensions from Device Manufacturer) available in the Store for free, and one can enable HEIF and HEVC support by installing the free pack as well. Interestingly, the free HEIF and HEVC Media Extensions from Device Manufacturer app is also released by Microsoft.
HEIF and HEVC became popular with the release of iOS 11 back in 2017 as Apple decided to use these new file formats to save pictures and videos to save storage space on iPhone and iPad.