In some cases, an extra driver is required for the display of HEIC files on some systems.
Please install the following driver: Download CopyTrans-HEIC Driver

Possible error pattern: CopyTrans HEIC tool for displaying HEIF files has been installed, but still no display or reading of HEIC files is performed.

Cause: Microsoft HEIF ImageExtension has also been installed and is blocking CopyTrans

Solution:

• From Windows - Start - Open "Command Prompt" or "Terminal" (As Administrator)
• Run command (confirm with Y): winget uninstall --name="HEIF Image Extensions"
• Possibly reinstall CopyTrans HEIC
• Test preview and display in Explorer or Photo Viewer
• In PictureGuide, go to Settings - Library again and read/update folders
• If the problem has not yet been solved, go through the steps a second time