The install may take 30–90 minutes. Do not close the lid or turn off your Mac.
Your System Preferences will open to the Software Update panel, displaying a prompt to download macOS Catalina. Click . how to update macos high sierra 10136 to 1015
The most critical operational change in macOS Catalina is the . High Sierra is one of the final versions capable of running older 32-bit legacy software. Once you migrate to Catalina, any remaining 32-bit programs will fail to open. The install may take 30–90 minutes
You will need at least 12.5GB to 18.5GB of available storage to download and install the installer. Step 3: Download macOS Catalina 10.15 how to update macos high sierra 10136 to 1015