Download+macos+1015+catalina+dmg+file+for+clean+installation+hot ((hot)) May 2026

Are you installing this on a or a virtual machine (like VirtualBox)? Which year/model is your Mac?

Plug the USB into the target Mac. Restart the Mac and immediately hold down the Option ( ) key . Select the "Install macOS Catalina" volume. Are you installing this on a or a

To perform a clean installation, you cannot run the installer while running the system you want to delete. You need a bootable USB drive (at least 16GB). Are you installing this on a or a

Crucial Step! Use Time Machine to back up all important files to an external drive. A clean install erases everything. Are you installing this on a or a

Enter your administrator password and type Y when prompted. Step 3: Performing the Clean Installation