Installing Operating Systems – CompTIA A+ 220-1002 – 1.3


The installation of an operating system requires a number of different configuration settings. In this video, you’ll learn about installation methods, partition types, file systems, and more.

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When you’re installing an operating system, you’ll need some type of boot media. One type that’s very common is to put the operating system files on a USB drive. The USB drive has to be bootable, and the computer you’re using has to be able to boot from a USB interface. But if you’re able to do those two things, you can plug into any available USB interface, start your computer, and start installing your operating system directly from USB.

Another common operating system installation media is a CD-ROM or DVD-ROM, but these drives are getting less and less popular. And so we’re seeing more of a move towards USB instead of CD or DVD. In larger scale environments, you may choose to put the operating system installation files on a central server, and then you would boot your computer to use something called Pixie– or PXE.

This is the pre-boot execution environment. As long as your computer is able to boot using a network interface card to a PXE server, you can use this pre-boot execution environment and not have to have any local installation media. If you’re using Mac OS, there’s a similar technology to Pixie called NetBoot, which allows you to install Mac OS across the network.

If you need to install many different types of operating systems, you may want to consider using some external media that you would connect to with USB. This allows you to install many different operating systems onto the single drive so you can take that drive with you anywhere and know that you have the operating system you need to install.

Some of these external drives even allow you to configure parts of that drive to act as an ISO image. This makes the drive look like a CD-ROM or a DVD-ROM image. So you can plug this large storage drive into a USB interface, but that the computer sees it as if it’s a DVD-ROM drive.

And another way to install the operating system is to have a separate partition on the same physical drive. You would have one partition to boot from to run the installation process, and that would install the operating system into a separate partition on the same drive. If you’ve ever installed Windows, you know that, during the installation process, there are no prompts that you have to answer. In some environments, it’s useful if you can have all of those prompts pre-answered and have the installation simply go through the entire process without any type of user intervention.

This is called an unattended installation. You would provide all of the answers in a single file called unattend.xml. And when you start the installation process, it goes from the very beginning to the very end without prompting you at any point along the way. As you can imagine, in a large environment, where there are many different installations occurring at the same time, this type of unattended installation can save a lot of time.

Some versions of Windows allow you to install a newer version of the operating system on top of the old version. This is called an in-place upgrade. And one of the benefits of doing an in-place installation is that you get to keep all of the applications and all of the configuration settings in place, and all you’re doing is simply changing the operating system from one version to another.

Some versions of Windows, however, don’t allow an in place upgrade. In those cases, you have to copy all of your personal information off of that drive and perform a clean install, where you’re effectively deleting everything that was previously on the storage device and installing a brand new version of the operating system. Once that clean installation is complete, you would then have to copy back your files to be able to gain access to those.

There are migration programs and tools that can help with this process that will automatically perform the backup, and then automatically restore that information once the clean install has completed. And in some organizations, you have very similar hardware and similar configurations that will be used on tens, hundreds, or even thousands of different computers. In those environments, desktop administrators create an image that they can quickly install onto many, many different computers simultaneously, allowing them all to have exactly the same configuration.

If you’re having a problem with your Windows configuration and you would like to reinstall the operating system, but leave all of your files and applications in place, you’ll probably want to run a repair installation. The repair installation looks and feels very similar to a normal Windows installation. But after it’s over, you’ll still have all of your files and all of your configuration settings in place.

Some people like to have the choice of running different operating systems when they start their computer. This is called a multiboot installation. The end user will install multiple operating systems onto the same storage device, and then choose which operating system to start during the bootup process. In most modern versions of Windows, when you install the operating system, Windows will also install a recovery partition.

This will take all of the Windows installation files and make a copy of those into a hidden partition on your computer. This is commonly used with a repair installation so that you can run the repair or run and install of Windows without needing to find the original Windows installation media.

This is the partition that’s used in Windows 8 and Windows 10 if you’re performing a refresh or restore of the operating system. You don’t have to look for your original installation USB drive or DVD-ROM drive. You would simply choose the Refresh or the Restore option inside of Windows, and Windows will pull all of that installation information from the recovery partition.

These partitions can be very useful when you’re trying to logically separate different parts of the same physical storage drive. Although you may find it useful to have separate partitions to be able to store different types of data, you may find that having separate partitions is not necessary for your specific installation.

One common use of having separate partitions on a storage device is when you’re installing separate operating systems. You might have one partition from one version of Windows, one partition for another version of Windows, and one partition for a Linux distribution. When you’re working inside of Windows, you may see these partitions referred to as volumes. And in the Microsoft world, a volume and a partition are effectively the same thing.

With older operating systems, you may find that the partitions are MBR partition style. This is Master Boot Record partitions. And if there is an older operating system that’s running on your computer, you may find that MBR partitions are what that operating system is using. These were separated into two different types of partitions.

The first type is a primary partition. These are partitions that are bootable by an operating system. So if you had multiple operating systems that were booted from a single storage device, each of those operating systems would have their own primary partition. With Master Boot Record partitions, you can have a maximum of four primary partitions per disk, and you would normally allocate one of those as being the active partition so that your system would know which operating system to boot from by default when you start your computer.

The other type of partition you can have in a Master Boot Record partition style is an extended partition. This is useful if you needed to create another partition that wasn’t necessarily bootable, but you would like to separate data into that separate partition. With MBR partitions you would create one single extended partition. And within that extended partition, you would create multiple logical partitions. It’s common in Windows to assign a drive letter to each one of these partitions so that you have a way to access and store files into those primary or logical partitions.

One limitation to these extended partitions is that none of these logical partitions that exist within that extended partition are bootable, so you would not be able to install Windows or Linux into one of these logical partitions, and then be able to boot from that operating system. If you need to boot an OS, you’ll need to install that operating system into a primary partition.

On most, modern operating systems we’re not using the Master Boot Record partition style. We’re instead using the GPT partition style. GPT stands for GUID Partition Table, where GUID is an abbreviation for a Globally Unique Identifier. A GUID is a unique number that is used to refer to a particular resource. And in most modern operating systems, we’re using this GPT partition style.

To be able to use a GUID partition table, you would need to be running a BIOS that is the newer UEFI BIOS, but this will allow you to have up to 128 partitions for a single storage device. This is very different than the Master Boot Record partitions, where you had extended and logical partitions. Instead, with GPT, all 128 of those partitions are bootable. So you can think of these as having 128 primary partitions.

This partitioning is important because this is the first thing you’re going to do before writing any type of information to the drive. Before you install an operating system, you have to first configure a partition there may be existing partitions that are already on the drive, so you might install the operating system into an existing partition, but you have to make sure the operating system is compatible with the partition that you’d be using.

As we mentioned earlier, we can have up to four partitions on the MBR– or Master Boot Record– style partition, and we can have up to 128 partitions if we’re using GUID partition tables. Just keep in mind that if we’re running a GUID partition table, then we must also be using a UEFI BIOS or a BIOS that has a BIOS compatibility mode. Some operating systems like Windows, though, will not boot in a BIOS compatibility mode. You must be using the UEFI BIOS with the secure boot capabilities.

There is one important thing to remember when you’re dealing with partitions. This is the fundamental storage area for all of your data. If you’re adding, removing, or making changes to any partition, you could potentially be removing data from that drive. Make sure that you always check your work before making any changes to your partitions.

If you’re performing a Windows setup, you may get a prompt like this that asks where you want to install Windows. And it may provide you with a completely empty drive that has no partitions installed at all, and then you can click the New button and build a brand new partition that you would use for your Windows installation.

Before adding a file system to a partition, Windows wants to know whether this will be a basic disk or a dynamic disk. A basic disk is one that’s very similar to the drives that we’ve always been using in DOS and Windows through the years. There are primary partitions, there may be extended partitions and logical drives, and you would not be able to take partitions and span them across multiple physical drives.

The Windows operating system, though, provide you with a number of different options for storing data on these drives. And you may want to configure this partition as dynamic disk storage. This is a feature available in most modern versions of Windows. This allows you to add multiple disk to your system and simply extend your partition across all of those physical drives seamlessly to the Windows operating system.

You can also split data across multiple disks– we call this striping– or you can duplicate data onto multiple disks– we call this mirroring. Some of these capabilities can provide additional performance or redundancy for your data. Not all of these dynamic disk options are available in all editions of Windows, so make sure you know what options are available for your specific Windows edition.

Once you’ve created a partition and decided on what type of disk you’re going to use, you then need to decide what type of file system you’re going to use on this partition. The file system is the way that your operating system is going to use to categorize and store all of the files that will be used on this storage device. Different operating systems expect you to write this data into a particular file system.

For example, Windows recognizes the FAT32 file system and the NTFS file system. And you’ll find that many operating systems can read and write multiple types of file systems. For example, Windows can read and write FAT, FAT32, NTFS, exFAT, and other file system types as well.

The file system FAT stands for File Allocation Table. This was one of the very first file systems we used in personal computers. The version that you most commonly see on the more modern operating systems is called FAT32. This allows for larger volume sizes. And larger is a relative term, since the maximum size is 2 terabytes.

On more modern operating systems, you’ll find the FAT32 file system, which allows maximum volume sizes of 2 terabytes and maximum file sizes of only 4 gigabytes. Microsoft extended FAT32 to create exFAT. This stands for Extended File Allocation Table. This is the file system that’s used on flash drives so that you can have files that are much larger than 4 gigabytes in size.

Because of the limitations associated with FAT32, you’ll commonly see NTFS used on most Windows systems. This stands for the NT File System, and it has a number of improvements over FAT32, not just the size of the partitions and the size of the files, but you can include quotas, there’s file compression built into the file system, encryption is built into the file system, and many more features as well.

If you’re using a CD-ROM drive or a DVD-ROM drive, then you’re probably using the Compact Disk File System– or CDFS. This is an ISO standard called ISO 9660. And it’s such a common standard that you can use the same CD or DVD-ROM drive on practically any operating system, and you would still be able to read that data.

If you’re using the Linux operating system, you may see file systems such as the ext3. This is the third extended file system. And even newer is ext4, for the fourth extended file system. You commonly see ext3 in operating system such as Linux. You might also see this running in the Android operating system.

If your operating system is storing files on a storage device that’s across the network, you may be using NFS, which is the Network File System. This allows you to access those storage devices across the network. But to your operating system, it looks like it’s a local drive that’s on your local computer. There are NFS clients available for almost any operating system you would run, making it a popular file system to use across the network.

If you’re running Mac OS, you may be using the HFS+ file system. This stands for Hierarchical File System. You may also see those referred to as the Mac OS Extended file system. On newer versions of Mac OS, specifically macOS High Sierra and later, you’re probably running the Apple File System– or the APFS.

On many of these operating systems, it’s common to have a swap partition. And although this is referring to a storage device, this is primarily used for memory management within the operating system. If you’re running a number of different applications in your operating system and you’re running out of available memory, your operating system can temporarily copy some unused information to the storage device in the swap partition.

Then when that information is needed again, it would be loaded back from the swap partition back into memory of your operating system. Because of the need to move this information so quickly in and out of the memory, we would commonly have a swap partition on the fastest drive or an SSD drive inside of your computer.

Now that you’ve built a partition, and you’ve decided the type of disk to use, and you’ve chosen a file system, it’s now time to initialize that file system by performing a format. There are generally two different types of formats that you would use. One is a quick format and the other is a full format.

As the name implies, a quick format quickly creates a brand new file table on your disk, but it doesn’t see race any of the data that may have already existed on the drive, and it doesn’t perform any physical check of the drive to make sure that the drive is in good working order.

If you’re running Windows 7, Windows 8 or 8.1, or Windows 10, this is the default format that occurs inside of the operating system installation program. If you need to perform a full format, then you’ll want to run the diskpart utility from the command line. The full format is going to take quite a bit longer to performance its initialization.

It will go through the entire drive and write 0s into every single sector of the drive, not only clearing out any data that may have previously been there, but it performs a check to make sure that it’s able to read and write data to every part of that storage device. If you’re concerned about the health of the drive or you would just like to be absolutely sure that this drive is ready for your files, you may want to perform that full format.

There may be other things that you need to consider during the installation process. For example, if your operating system doesn’t recognize the controller that a storage device is plugged into, you may need to provide additional drivers during the installation process so that the install program can properly access those storage drives. In Windows, you may be asked whether this will be a workstation configuration or a Windows domain configuration. And if you are connecting to a Windows domain, you’ll need the proper credentials to be able to add that device to the network.

The operating system also wants to confirm the time zone, the date and time, information about where you may be located, and any language settings you may need for that operating system. Most operating system installation programs will recognize the hardware that’s used inside of your computer, and it will load the appropriate drivers. But if you’re using hardware that’s not automatically recognized by the install program, you’ll need to provide those drivers either during or after the installation is done.

After the initial installation is complete, you may also want to perform a Windows Update, just to make sure you’re running the latest version of the operating system with all of the most recent security patches. And if the operating system that you’re using hasn’t created its own recovery partition, you may want to create one yourself. You can copy all of the files you just used into that recovery partition. That way, if you run into a problem later, you won’t have to hunt around for that installation media.