Image Files (ImageMagick)
Windows install location
If magick isn't on PATH, it's installed at:
C:\Program Files\ImageMagick-7.1.2-Q16-HDRI
Call it with the full quoted path.
Modern vs legacy syntax
Try modern ImageMagick 7 syntax first (magick input.jpg -resize 800x output.jpg, magick identify); fall back to legacy IM6 commands (convert, identify, mogrify) if magick isn't found.
Full option syntax is available via magick help.