1. Mac Os Reboot Recovery
2. Force Reboot Mac Os
3. Download Reboot Mac Os Flash Drives

I purchased a used 2018 Mac mini desktop and wanted to put a fresh installation of the latest macOS 10.15 Catalina on it. Below are the steps I took.

Note: The instructions below are the same for macOS 10.13 High Sierra and macOS 10.14 Mojave.

Download macOS Catalina

How to Create a Bootable Mac OS X Flash Drive. A copy of OS X Lion, you should be able to download a fresh copy at any time from the Purchases tab of the Mac App Store. Mac Free USB Flash Drive Recovery helps you easily recover all lost missing files and folders from your USB media due to wrong deletion, format, power failure, virus infection or USB damaged, etc. Apple released the new Mac OS X 10.10 Yosemite in the Mac App Store for everyone to download and install for free on October 16th, 2014, but downloading a 5+ GB file for each of your computers will take some serious time. The best thing to do is download it once and create a bootable install USB drive from the file for all of your Macs.

You will need a Mac to download macOS Catalina. (The Mac mini came with macOS 10.14 Mojave so I used it to download Catalina.)

Go to the Mac App Store, search for “macOS Catalina”, and download it. It will be saved to the “/Applications/Install macOS Catalina” location. If the installer automatically launches, just close it.

Note: If you plan to run the installer first to update your current macOS version to Catalina, you will want to move the “Install macOS Catalina” application out of the “/Applications” directory; otherwise, the installer will delete itself from the “/Applications” directory when the upgrade completes. For example, you can move the “Install macOS Catalina” application to the “~/Downloads” directory and run it from there.

Format USB Flash Drive

Because macOS Catalina is 8.4GB in size, you will need a 16GB USB flash drive. You don’t need to delete the existing content on the drive because we will blow it all away in a subsequent step.

If the USB flash drive is not already formatted as “Mac OS Extended (Journaled)”, format it like so:

1. Plug the USB flash drive into your Mac.
2. Launch the “Disk Utility” application.
3. On the left-hand pane, select the USB drive (not the partition under it, if any).
4. Click on the “Erase” tab (or button at the top).
   1. Input a name like “Catalina” (this name will be overwritten later).
   2. Select “Mac OS Extended (Journaled)” for “Format”.
   3. If available, select “Master Boot Record” for “Scheme”.
   4. Click the “Erase” button at the bottom. Click the “Erase” button in the warning popup dialog if you get one.
5. The format operation may take several minutes to complete. (USB 2.0 and large capacity drives may take longer.) After the format completes, the partition will be mounted under “/Volumes/Catalina” (or whatever name you selected above).
6. Close the “Disk Utility” application.

Write macOS Catalina to USB Flash Drive

To create a bootable USB macOS Catalina installer, run the “Terminal” application and this command:

Note: If the createinstallmedia command returns a “Failed to start erase of disk due to error (-9999, 0)” error, then your current Mac OS X version does not fully support the createinstallmedia tool. Use a more recent macOS version (at least Mac OS X 10.11 El Capitan) or manually create the USB installation drive using instructions from Bootable USB Flash Drive to Install Mac OS X 10.10 Yosemite.

The “createinstallmedia” program will erase the USB flash drive, create a new partition named “Install macOS Catalina”, and copy the installation files to that partition. The output will look like:

The above process took 20-30 minutes using my Kingston USB 2.0 flash drive.

Boot From USB Flash Drive

Note: Apple’s How to create a bootable installer for macOS page suggest using the “Startup Disk” configuration (under “System Preferences”) to select the USB flash drive as the startup drive. Then on restart, the Mac should boot from the USB flash drive. Unfortunately, the “Startup Disk” did not list my USB flash drive as a startup option, so I was not able to use this method.

To boot a Mac with the USB flash drive:

1. Insert the USB flash drive.
2. While holding the “option” key down, turn on the Mac to display the Startup Manager.
3. You should see one or more icons, one of which should be called “Install macOS Catalina” for the USB flash drive. (The internal hard drive may not be visible if it does not have a valid, bootable partition installed.)
   • Note: If you don’t see the USB flash drive’s “Install macOS Catalina”, try removing and re-inserting the USB flash drive while viewing the Startup Manager screen. The USB flash drive should then appear after a few seconds.
4. Select the “Install macOS Catalina” (with left/right arrow keys) and hit the “return/enter” key to boot from the USB flash drive.

It may take 5-10 minutes to load the installer from the USB flash drive. Sometimes the progress bar may appear to be frozen or the screen will go black for a minute or two. Be patient.

External Startup Disk Not Allowed

On a newer Mac with the T2 security chip, booting from an external drive may be disallowed by default. Attempting to boot from a USB flash drive will result in a “Security settings do not allow this Mac to use an external startup disk” warning message.

To allow booting from the USB flash drive, do the following:

1. Hold down “Command-R” (hold down both the “Command ⌘” and “R” keys) when you start the Mac to launch macOS Recovery. You can release the keys when you see the Apple logo.
   • Tip: An easier alternative is to hold the “Option/Alt” key on boot to launch the Startup Manager. Then just click and release “Command-R” keys to launch macOS Recovery.
2. The macOS Recovery screen contains a top-level “macOS Utilities” menu.
3. Click on the “Utilities” menu and select “Startup Security Utility”. Input your administrator password when prompted.
4. In the Startup Security Utility, under “Allowed Boot Media”, select the “Allow booting from external or removable media” option.
5. If the Mac won’t have access to the Internet (either by wire or wirelessly) when installing macOS Catalina, make sure to select either the “Medium Security” or “No Security” option under the “Secure Boot” section. (You can change the option back to the default “Full Security” afterwards.)
6. Quit the macOS Utilities to restart the Mac.
7. On restart, follow the directions in the previous section to boot from the USB flash drive.

Erase the Internal Hard Drive

When the installer finishes loading, you will see a “macOS Utilities” screen appear. It looks the same as the “macOS Recovery” screen with one difference. In the “macOS Utilities” window, the second option will say “Install macOS” instead of “Reinstall macOS”. In “macOS Recovery”, the “Reinstall macOS” option would just re-install the same version of macOS. The “Install macoS” option will install the macOS Catalina version on the USB flash drive.

Mac Os Reboot Recovery

Before installing macOS, I wanted a clean slate so I erased the internal hard drive like so:

1. Select the “Disk Utility” option and click the “Continue” button on the bottom to launch the “Disk Utility” application.
2. On the left-hand pane, select the internal hard drive (not the partition under it, if any).
3. Click on the “Erase” button at the top.
   1. Keep the default “Macintosh HD” name or input a new one.
   2. Select “APFS” for “Format”.
   3. Click the “Erase” button at the bottom. The SSD (Solid State Drive) format took less than a minute to complete.
4. Close the “Disk Utility” application.

Install macOS Catalina

Warning: If your Mac has a T2 security chip and you left the “Full Security” option configured in the Startup Security Utility, make sure that Internet access (wired or wireless) is available before starting the macOS Catalina installation. You can configure the wireless network by clicking on the wireless icon at the top-right corner of the macOS Utilities screen.

Back at the “macOS Utilities” window, do the following to start the macOS Catalina installation:

1. Click on the “Install macOS” option and click the “Continue” button.
2. The “macOS Catalina” installer’s splash screen will appear. Click the “Continue” button.
3. Click on the “Agree” button to agree to the license. A popup confirmation window will appear; click on the popup’s “Agree” button.
4. Select the internal hard drive and click the “Install” button.

My Mac mini took 20-30 minutes to complete the macOS Catalina installation. I think there were a couple of reboots in-between. And a few times, the screen would go black for a minute or two. Be patient and give the process an hour or more to complete.

If you run into problems installing macOS Catalina, check the “What Does Giving Up Mean?” section (at the bottom) of Install macOS Sierra Using Bootable USB Flash Drive for possible solutions.

Note: macOS Catalina seems to have an issue with my Dell 24in U2410 monitor. During the initial bootup screen, the monitor shows a blank screen with a message, “The current input timing is not supported by the monitor display”. Thankfully, the monitor works correctly after the bootup completes. And later, this warning message no longer appeared on bootup.

Enjoy your fresh installation of macOS 10.15 Catalina.

Summary: Are you dealing with a crashed Mac or unable to boot your Mac machine?
Before you think of reinstalling macOS or doing a hardware fix, ensure that you’ve rescued your data from the device.
This blog will guide you through an easy process of creating a bootable macOS Mojave USB install drive or a recovery USB drive using Stellar Data Recovery for Mac software.
The USB recovery drive will help you to recover the data from your crashed or non-booting macOS. So go ahead, download the free software trial now.
Minimum requirement: 8 GB USB flash drive, Mac, and Mojave installer.

1. Download macOS Mojave 10.14 from App Store.
2. When the download completes, quit the installer, as it will launch itself automatically.
3. Locate the installer from the Applications folder (copy it to the desktop if you desire).
4. Connect the USB flash drive with at least 8 Gigabytes storage space to your Mac.
5. Open Terminal and enter the next command: sudo (drag and drop the installer from application folder to locate its path) –volume (drag and drop the USB flash drive from the Mac volumes to specify its path) –nointeraction –downloadassets

Warning: The command erases the flash drive so check there are no stored files; backup the files, if they exist, before executing the sudo command.

1. Type the administrator password when prompted. The Terminal creates the installer drive on the opted USB flash drive.

Note: Erase the flash drive to HFS+ (Mac OS Extended (Journaled)) but not APFS.

Usage of USB Install Drive

1. Backup the entire drive before performing a clean install on your Mac machine.
2. Connect the USB install medium.
3. For T2 security chip supported by 2018 MacBook Pros and iMac Pros, you need to “allow booting from external media” from Startup Security Utility. Alternatively, hold the option key and reboot the Mac then use the arrow key to select the USB flash drive as an installer.
4. Allow the computer to boot from the USB flash drive. Deploy the macOS Mojave software.

Installer Tips

• When Apple releases newer Mojave versions, re-download the new installer and recreate installer drive to keep it up to date.
• Keep the installer drive on a safe place so that you can use it as an external recovery drive when your Mac gets into trouble.

Data Recovery on macOS: Why We Need It Here

While performing macOS upgrade or fresh installation, you must back up data to an external storage medium. Backup helps to restore all the data back to Mac’s internal storage drive, containing the new macOS. If you do not have a backup, then you end up losing all your data stored in the Mac drive. This is because, during macOS installation, the installer erases the startup partition completely or the entire storage drive, depending upon your choice during installation.

If No Backup: What Is the Recourse?

There are chances that you did not take backup to an external backup drive, or in the rare case, the backup itself was lost, damaged, or unavailable. In such scenarios, you can rely on a data recovery software—such as the editor’s choice Stellar Data Recovery Professional for Mac—that can recover your lost data after macOS Mojave installation. The software works flawlessly with the older & newer version of MacBook Pro, MacBook Air, iMac, iMac Pro, and Mac Mini etc.

The Process of Data Recovery

The process of data recovery is straightforward. Follow the steps mentioned below to get back the data stored in the drive—erased completely after installing the new macOS Mojave:

1. Download and install the Mac data recovery utility on the same system where you have installed the new macOS Mojave (due to the negligible storage requirement of the utility).

2. Alternately, you can download and install the utility on a different Mac machine, then connect the internal drive as an external device by removing it from the affected Mac.

3. Launch the data recovery software to interact with its lucid graphical user interface.

4. In the Recover Data module, select the type of data and the location of the storage drive.

5. Toggle on the Deep Scan switch from the bottom left and click the Scan

6. Allow the scan to complete, which may take some time—depending on the storage size and the condition of the affected drive.

7. Preview the recoverable files if you want, then select all the required files and click the Recover

8. Specify a different external backup drive with size greater than the drive where you are performing the data recovery then click Save.

When the save process is complete, verify the recovered data from the backup storage drive. Copy the files back to your Mac or an externally used Mac drive (reconnect the drive to the Mac once the restoration process is over).

Activation of the Software

Force Reboot Mac Os

You must activate Stellar Data Recovery Professional on your Mac in order to save the recoverable files. The free download version of the software is a good way to know the software’s interface, scan your drive, and preview the recoverable files.

Download Reboot Mac Os Flash Drives

Watch the activation video of Stellar Data Recovery Professional to know how to activate the software and use its complete functionality, including the complementary Drive Monitor, on your iMac or MacBook system.

Conclusion

The blog highlighted the need for recovery drive, steps to create a bootable USB flash drive, and usage of the drive for installing the new macOS Mojave 10.14 in one or multiple computers. The drive acts as an external recovery drive in case your Mac fails to boot. In addition, the drive acts as a means to fresh install the drive to boost the performance of your slow, virus-infected, or troubled Mac. The blog also suggested a data recovery software that can help recover data lost due to macOS Mojave installation on your desktop or notebook computer.