Adobe explains that opening an HEIC file on Windows requires updating to Windows 10 version 18.09 or later and then installing an extension to add HEIC support. HEIC files: How to create, edit and open them - Adobe
Add the Windows-incompatible HEIC photo to the upload box below to begin the fix.
HEIC To PDFHeic File Won't Open On Windows
One documented workaround is switching the iPhone Camera setting from High Efficiency to Most Compatible so photos save as JPG instead of HEIC in the first place. Article - Can't open HEIC File - Normandale Community College
Open the Settings app on your iPhone.
Tap Camera in that same Settings app, then tap Formats listed underneath it in the menu.
Select Most Compatible to save future photos as JPG.
Converting HEIC to PDF for Windows
HEIC To PDF names its output file with a "_HEICToPDF.pdf" suffix, confirming the result is a standard PDF that any Windows PDF viewer can open.
Click the convert button to process the image.
Save the converted PDF onto the Windows machine for testing.
Opening The Result On Windows
The reset control removes the current upload in place, with no page reload, freeing the page to check a second HEIC for Windows compatibility.
Open the downloaded PDF in a viewer.
Review the image quality and orientation.
Continue with Preserving Orientation in HEIC to PDF or Convert HEIC to Searchable PDF.
Frequently Asked Questions about Why HEIC Photos Won't Open on Windows
How do I convert a HEIC file to PDF?
Upload the HEIC file and click convert.
Where do I find the converted file?
Open the downloads folder to grab the newly converted PDF.
How do I reset the tool for another photo?
Click the start-over option after downloading.
How do I prevent HEIC files on my iPhone?
Set the camera format to Most Compatible in iPhone settings.