Final answer:
To factory reset macOS Catalina 10.15.7, go to the Apple menu, select 'Restart', hold down Command and R keys, choose 'Disk Utility' and erase the startup disk with a new name and format. Then, select 'Reinstall macOS' from the macOS Utilities window.
Step-by-step explanation:
To factory reset macOS Catalina 10.15.7, follow these steps:
Go to the Apple menu and select 'Restart'. While the Mac is restarting, hold down the Command and R keys together until the Apple logo appears. When the macOS Utilities window appears, select 'Disk Utility' and click 'Continue'. In Disk Utility, choose your startup disk and click on the 'Erase' tab. Enter a name for the disk and choose 'Mac OS Extended (Journaled)' as the format. Click 'Erase'. Once the disk is erased, go back to the macOS Utilities window and select 'Reinstall macOS'. Follow the onscreen instructions to complete the reinstallation process.
It is important to note that a factory reset will erase all the data on your Mac, so make sure to backup any important files before proceeding.