# Step by step - complete guide to reinstall macOS system after deleting :

One of the most difficult problems that you may encounter if you have a Mac in all its versions, which is the problem of deleting the system from the device.

Many cases that cause the system to be deleted from the device is due to the internal hard disk, specifically HDD-type hard drives.

Where the simplest problem may lead to damage to the hard disk because it is very sensitive due to the structure of its manufacture.

We will solve the problem for you in this article, where we will learn step by step the best possible way to reinstall macOS system after deleting it from the device.

What I need before to reinstall macOS from scratch?

In order to be able to reinstall the Mac system on your device, you will need to download some files that you need.

So you must be connected to the Internet, we will attach to you in the table all the files you need to start the process of reinstalling the system.

In this method, you can reinstall macOS without firmware password, so the installation process will be smooth and without problems, we hope so.

The additional things that you will need is a flash drive with a capacity greater or equal to 8 GB.

Because we will reinstall macOS from USB, so make sure that you transfer all your files to another flash or any other device because we can't reinstall mac os without losing data with this method.

You will also need a device with Windows installed, because the program that we will use in order to reinstall macOS from scratch is a program for Windows, so you will have to provide the device to complete the process.

If you have another macOS device work without any problem, And you don't have a Windows device, you can use virtual machine that allow you to install the Windows system, which will enable you to reinstall macOS without problems.

We can't reinstall mac os without losing data, so if your macOS device is work, but you decided to install clean macOS system , make sure that you transfer all your important data to another device.

Required device	Windows(7 , 8 , 10+) or virtual machine
macOS Lion	Download - pass: shamelnet48
TransMac program	Download
USB capacity	8 GB or more

How times take to reinstall macOS completely?

Reinstall macOS taking too long, from one to two hours, so you should be patient during the reinstallation process, and you should also be present in front of your device sometimes to complete some necessary steps.

You will go through a number of stages while reinstalling the Mac system on your device.

We will explain this in detail in its special section, so you must have some capabilities in dealing with the device, but do not worry, the method is very easy if you follow the explanation step by step.

Does When erase hard drive and reinstall macOS will delete everything?

When you decide to do the work of reinstalling the system on your device, you will ask the following question, if I reinstall macOS will I lose everything?

The answer is yes, in short.

If you decide to reformat the Mac and restart your device, the most logical reason is that your device literally does not turn on, or stops at the Apple logo, or shows you an empty file while the device is running, and many other problems. 

And the small percentage of those who want to reinstall the system while their device is working, may be because the device is slow during operation, or they have had any malfunctions in the internal system, or they are exposed to the threat of a virus or the threat of penetration. 

According to my personal experience, the most common reason for Mac system failure is because of the hard disk, specifically the hard disk of the HDD type, as the latter is easy to damage and often leads to slow device or damage to the entire system. 

Therefore, it is always recommended to buy an SSD hard disk, as it is characterized by great speed while operating or working on the device, and it is less damaged compared to an HDD, and the system has very few system malfunctions.

Are there other ways to reinstall the system macOS other than this method?

As far as I know, there are two methods other than the method that we will explain in this article, but they need some things that must be available in order for these methods to succeed.

Install macOS system from time machine

One of the ways I like to install the system is that you can restore macOS from time machine.

But this method it has two fatal flaws that must be present in order to be able to make the process successful without problems.

The advantage of installing the Mac system through a time machine is that it makes a full backup of the system and its files.

So you must have an external hard disk greater or equal to the capacity of the hard disk in your device.

The second thing is that you must have a working Mac in order to make a system backup from it, otherwise you will not be able to because the tool is only available on Macs.

Install macOS system from macOS recovery mode

You can reinstall macOS from internet via recovery mode, so you must make sure that your internet speed is fast, so that there is no interruption when downloading the system, and the system is installed without problems.

But if you can't reinstall macOS from recovery mode, this guide will help you to solve the problem.

How I can reinstall macOS from a USB drive?

So, after all this talk, we have reached the important point, so make sure that you read َall the question that we raised earlier in the context of the article and that we answered, so make sure that you read it carefully. 

Now we will start explaining how to reinstall the Mac system from scratch.

After reaching this point, you have currently provided a Windows device, and you have downloaded the TrancMac program on your device and installed it, and after that you downloaded the system that we will burn on the flash drive.

After all the requirements are available, decompress the system files on your device through one of the decompression programs (WinRAR), and then install TrancMac on your Windows computer.

Put your flash drive (USB) on the Windows device, and make sure that the flash drive is greater or equal to 8 GB in the internal space.

Now open TrancMac and give it all the required permissions, you will notice that the flash drive (USB) appears inside the program.

Go to the flash option with the mouse, then click on the right mouse button to show the additional options for the program.

Many options will appear for you, and the option we need is (format disk for mac), as its task is to do the formatting of the flash so that you can burn the Mac system on the flash without problems.

After clicking on the option, a message will appear asking you to give the program the authority to modify the flash and make a full format for it and prepare it to burn the Mac system on it.

Just click on the option (Yes).

TrancMac will do a restart, but this time with full permissions to perform the formatting process.

We will repeat the same previous process, where we click from the flash on the right button of the mouse, then we click on the option (format disk for mac) to start the formatting process.

A confirmation message will appear to you that the operation you will perform on your flash drive will make a full scan of the files inside the flash.

So make sure to move all files to another place before performing the operation.

So, now a window will appear asking you to name your hard disk with any name you want to start the formatting process, then press OK to start the formatting process.

Now, after making a full boot of the flash, it will be time to do the work of burning the system on the flash.

As a side note, the burning process will take some time, so during the burning process you can go and do anything you want.

We put the mouse on the flash drive and then press the right button of the mouse in order for you to see side options, and from it, we will choose (Restore with Disk Image).

A window will pop up for you to confirm that you are sure of what to do, so click (ok).

Now a new window will appear, where it will ask you to choose the system file you want to burn on the flash drive.

You must make sure that you have decompressed the files before completing the process, and to make sure that the file that you will put in the program is the correct file, you will find that the file extension is (.DMG)٫ 

So check the file before adding it.

After selecting the file, click on (open).

After selecting the system file and pressing open the file, the process of burning the system files on the flash drive (USB) will start.

As a side note, the process will take some time to finish, so you can let the program do its work, and you can go and do something.

After the process of burning the Mac system on a flash drive, a message will appear to you that the burning process was completed successfully.

So you can remove the flash from the device through the system, and do not remove it directly so that there are no problems in the future.

Now go to your Mac and put the flash drive in one of the USB ports of the device.

Turn on the device from the power button, and immediately after pressing the power button, press the (Alt) button without removing your finger from the (Alt) button.

After a period of time (about 15 seconds to 30 seconds) you should have seen a flash option on the Mac screen.

As a note, if you do not have shown the flash drive (USB) on the Mac screen, I will leave you at the bottom of the article some solutions to try.

Do not bother with the image above, it is only to explain the appearance of the flash on the screen of the Mac.

So choose the flash drive that we burned the system on, but in many cases the flash will appear on its own.

After pressing the flash, we will enter the recovery mode, so here the important process begins, so be sure to follow the explanation as it is, because there are some important steps that must be implemented correctly.

We will enter the recovery mode, a new window will appear, from which we choose (Disk Utility), and this is the most important step that must be done correctly.

In this video, it will help you to know how to fully format the device's hard disk to start the installation process

Then it will lead you to the beginning of the process of installing the system, and all that remains is to wait for the system to finish installing and then start using your device.

What I do if my USB drive not showing in my Mac?

It is very likely that the flash USB will not appear on your Mac after burning the system on it, so try the following tips so that you can skip this step.

• Change the flash if you have another one.
• Re-burn the system on the new flash.
• Insert the flash drive into a USB port other than the one you used before.
• Make sure that the system files you download are not corrupt and do not give errors while decompressing them.

What I do after install the system into my Mac?

Congratulations to you that your device is now working.

Check now if your device accepts the update to the latest existing system.

So if you reached this step and want to install a newer system for your device, write a comment to me in order to provide you with a version of the system that is compatible with your device.