Rob's HEIC to JPEG is a Windows program that converts HEIC files to JPEGs.
When run, a small window opens. Drag a heic file or folder of heic files onto the window and it creates a copy of the files but in jpeg format. That's it.
Note: If you have issues, you likely need to install HEIC Image Extension from: https://apps.microsoft.com/detail/9pmmsr1cgpwg?hl=en-US&gl=US