This step copies the installer files into the DMG. You will need your admin password.
# 1. Create a blank disk image on your desktop hdiutil create -o /tmp/Catalina -size 8500m -volname Catalina -layout SPUD -fs HFS+J # 2. Mount the newly created blank image to your system hdiutil attach /tmp/Catalina.dmg -noverify -mountpoint /Volumes/Catalina # 3. Flash the official installation files onto the mounted image sudo /Applications/Install\ macOS\ Catalina.app/Contents/Resources/createinstallmedia --volume /Volumes/Catalina --nointeraction # 4. Unmount the newly created bootable volume hdiutil detach /Volumes/Install\ macOS\ Catalina # 5. Convert the DMG file format into a standard ISO/CDR format hdiutil convert /tmp/Catalina.dmg -format UDTO -o ~/Desktop/Catalina.cdr # 6. Rename the file extension from .cdr to .iso to finish the process mv ~/Desktop/Catalina.cdr ~/Desktop/Catalina.iso # 7. Clean up temporary files left behind in the tmp directory rm /tmp/Catalina.dmg Use code with caution. Download Macos Catalina 10.15.7 Iso File --39-LINK--39-
Once the final command runs, a clean file will appear directly on your Mac desktop, ready for transfer to your Windows PC or virtualization server. Method 2: Direct Download Options for Windows Users This step copies the installer files into the DMG
The string --39-LINK-- in your query resembles forum shorthand for a password-protected or multi-part download link—often from abandonware or torrent sites. Realities: Create a blank disk image on your desktop