magick *.jpg -resize 800x600 resized_%d.jpg
Once you have extracted the portable version, you can run commands directly from the terminal (Command Prompt or PowerShell) by navigating to that folder: ImageMagick Binary versus Portable #7454 - GitHub imagemagick portable
Also, because portable apps don't have a formal uninstaller, always scan your portable drive for malware before using it on a new machine. Download only from PortableApps.com or the official ImageMagick GitHub releases (look for the *-portable-Q16-HDRI-x64.zip assets). magick *