Let’s start the guide of how to reinstall macOS Catalina/Mojave on Mac, iMac, MacBook Pro/Air. Step #1: “Shut Down your Mac” then start again or “Restart.” After your Mac plays Startup sound, “Press and hold (Command + R)” continuously. You will see Apple Logo with process bar, Still, press and hold both key.

Jan 11, 2019 · 1. Restart your Mac using one of the following keyboard commands: Command+R — this will reinstall the version of the OS that was most recently installed on your Mac. Command+Option+R — this will reinstall the latest version of the OS that is compatible with your Mac. 2. Macs can reach out over the internet and bootstrap themselves back into operation, as the Mac firmware—software built into a Mac that’s persistent and isn’t dependent on the operating system Jun 11, 2019 · If your Mac is missing a Recovery partition, then you may be able to restore it, by resetting your PRAM. To reset the PRAM, restart your Mac while holding down the ‘Command+Option+P+R’ keys until you hear macOS’ distinctive startup chimes for a second time. But they’re also what you do if something really bad happens to the copy of OS X that you boot your Mac from, or if the version of OS X on your Mac is earlier than 10.10 El Capitan. In other words, these instructions describe the process for installing, reinstalling, or upgrading OS X El Capitan. Here are the proper steps to follow to reinstall mac OS Catalina. 1. Back up your Mac first. By default, the best thing you could do before making any significant changes to how your Mac works is to back it up. Backups are just like saves before encountering challenges in video games — represent the point you can always come back to.

Reinstall Mac Operating System From The Recovery Partition. Turn on the Mac and immediately press and hold down both the Command key and the R key. Once you see the Apple logo appear in the middle of the screen you can release the Command and R keys. When the Mac has completed its startup, you should see a window similar this one:

Apr 15, 2014 · Continue to keep these buttons held until you hear the Mac startup chime twice. After the second chime, let go of the buttons and let your Mac restart as normal. No user data will be lost in this process. Resetting your PRAM will not only fix this particular OS X install issue, but it can also fix network issues, sound issues, and display issues.

Important: To reinstall macOS, you must be connected to the Internet.In the menu bar, choose Apple menu > Restart. Select Disk Utility, then click Continue.Select your startup disk on the left, then click Erase.Click the Format pop-up menu, choose Mac OS Extended, enter a name, then click Erase.

Jun 03, 2020 · If your Mac doesn't start up all the way, or you also want to restore the macOS you were using when you created the backup, follow the steps to restore both macOS and your files. When you're asked how you want to transfer your information, select the option to transfer from a Mac, Time Machine backup, or startup disk. Then click Continue. In that mode, when you choose to reinstall without erasing the drive, my recollection is that Recovery looks for the current OS system installer on your startup disk in the Applications folder Oct 07, 2019 · This step is important. An Internet connection is needed in order to reinstall the macOS operating system. If you are using a laptop, make sure it is connected to a power source. How to install a new copy of macOS Catalina in Recovery Mode. Recovery Mode is the special salvation of the Mac that first launched with OS X 10.7 Lion. If you have a problem with your Mac and need to reinstal the operating system you should be able to simply reinstall macOS (or Mac OS X) via the Recovery partition. In this article we'll look at Mar 04, 2019 · From the menu that appears, select the icon of the USB stick containing the operating system (which should be called Install macOS). From here, start the Disk Utility tool, select the Mac disk icon on which to install the OS via the left sidebar and press Format.