Installing an OS
Installing Windows or Linux from bootable media
Introduction
You have built a powerful machine. You have configured the BIOS/UEFI and verified that all hardware is recognised. But your computer still cannot do anything useful — because it has no operating system. An OS is the master program that manages all hardware and software, providing the interface through which you interact with the computer.
The two most common operating systems for personal computers are Microsoft Windows (used in most desktops and laptops worldwide) and Linux (a free, open-source OS popular with developers, servers, and enthusiasts). Both can be installed using a bootable USB drive containing the OS installation files.
In this chapter, you will learn how to create bootable installation media, partition a drive, and walk through the installation process for both Windows and Linux.
How It Works
Installing an OS is like moving into a new house. You have built the house (assembled the hardware), checked the utilities (BIOS/UEFI), and now you need to furnish it with furniture and appliances (the OS). The bootable USB drive is like the moving truck that brings everything in.
Household Object Analogy
Think of a computer without an OS like an empty plot of land. The hardware is the land itself. The BIOS/UEFI is the surveyor who checks the land is ready. The OS is the house you build on it — it provides the structure, rooms, doors, and windows (the interface) that let you actually live in and use the space.
Deeper Dive
To install an OS, you need a USB drive (8 GB or larger) containing the OS installation files. The USB must be made bootable — formatted and configured so the computer can boot from it.
Windows (Media Creation Tool)
Download Microsoft's Media Creation Tool from the official Windows download page. Run it, select "Create installation media for another PC", choose your language and edition, and select USB flash drive. The tool downloads Windows and writes it to the USB automatically.
Linux (Rufus / Balena Etcher)
Download a Linux distribution ISO file (e.g., Ubuntu, Linux Mint, Fedora). Use a tool like Rufus (Windows) or Balena Etcher (cross-platform) to write the ISO to a USB drive. Select GPT partition scheme and UEFI target system for modern hardware.
The Installation Process
Once the bootable USB is ready, insert it into the new PC and boot from it (set boot order in BIOS or use the boot menu key, often F12). The installer will guide you through the process:
1. Language and region: Choose your language, time, and keyboard layout.
2. Install now: Enter the product key (Windows) or choose installation type (Linux).
3. Partitioning: Select the drive where the OS will be installed. This is where you choose between automatic or manual partition setup.
4. Copying files: The installer copies OS files to the drive and prepares the system. This takes 10–30 minutes depending on drive speed.
5. Reboot: When prompted, remove the USB drive and let the system boot from the newly installed OS for the first time.
Partitioning Explained
Partitioning divides a physical drive into logical sections, each behaving like a separate drive. For UEFI-based systems with GPT, Windows typically creates several partitions:
EFI System Partition (ESP)
A small FAT32 partition (100–500 MB) that stores the UEFI bootloaders. Required for booting in UEFI mode. Marked with partition type GUID for EFI.
MSR (Microsoft Reserved Partition)
A small (16 MB) partition used by Windows for internal management. Not visible in File Explorer. Created automatically during Windows installation.
Primary (C:) Partition
The main partition where Windows, programs, and your files live. Formatted as NTFS (NT File System) — the native file system for Windows, supporting large files, permissions, and compression.
For Linux, the structure is different. Common partitions include: / (root) — the main system partition, usually formatted as ext4; /boot/efi — the EFI partition; and swap — a partition used as virtual memory when RAM is full. Some users create a separate /home partition so personal files survive OS reinstallation.
Post-Installation First Boot
After installation, the system boots into the OS for the first time. For Windows, you will go through the Out-of-Box Experience (OOBE) — creating a user account, connecting to Wi-Fi, and configuring privacy settings. For Linux, you will be greeted by a setup wizard that may ask for your username, password, and timezone.
At this stage, the Boot Manager (part of UEFI) keeps track of which OS to load. If you install multiple OSes (dual-boot), the boot manager presents a menu at startup letting you choose which one to run.
Key Insight
If the installer cannot find any drives, you may need to load storage drivers (especially for Intel VMD or AMD RAID configurations). On Windows, click "Load Driver" during the drive selection screen and browse to the extracted driver files on another USB. On Linux, the installer usually includes these drivers.
Advanced
At a deeper level, installing an os involves rules and patterns that engineers use worldwide. OS follows standards so different brands and devices can still work together. That is why your phone, school laptop, and game console can all connect to the same network or use the same apps.
Bootable USB does not happen in a straight line. Systems often use backup paths, error checking, and retries so information arrives correctly. When something fails, smart ISO design helps the system recover instead of shutting down completely.
Scientists and engineers keep improving these systems every year — making them faster, safer, and more energy-efficient. The ideas you learn in this chapter are the same building blocks used in real data centers, robots, apps, and websites around the world.
Vocabulary Table
| Term | Definition |
|---|---|
| OS | Operating System — the master software that manages hardware, runs applications, and provides a user interface |
| Bootable USB | A USB drive formatted and configured to boot a computer and run an OS installer |
| ISO | A disk image file containing the complete contents of an optical disc, used for OS distribution |
| Partition | A logical division of a storage drive that functions as a separate independent unit |
| File System | The method and structure used by an OS to organise, store, and retrieve files on a drive |
| NTFS | New Technology File System — the primary file system for Windows, supporting large files and permissions |
| ext4 | Fourth Extended File System — the default file system for many Linux distributions |
| Boot Manager | A UEFI component that allows the user to select which OS to boot in a multi-boot setup |
| GPT | GUID Partition Table — a modern partitioning scheme required for UEFI boot and drives over 2 TB |
| OOBE | Out-of-Box Experience — the initial setup wizard that runs the first time you boot a new OS |
Fun Facts
Windows 95 was installed from 13 floppy disks! A single Windows 11 installation ISO is over 5 GB. Modern installers fit on a USB drive smaller than a single floppy disk.
Linux was created by Linus Torvalds in 1991 as a personal project while he was a university student in Finland. He originally called it "Freax" (a portmanteau of "free" and "freak"). The name Linux came from the combination of "Linus" and "Unix".
Windows 11 requires a TPM 2.0 (Trusted Platform Module) chip and Secure Boot capability. This was the first time Microsoft mandated specific security hardware for a consumer Windows release, causing many older PCs to be officially unsupported.
The NTFS file system was introduced with Windows NT 3.1 in 1993. It supports individual file sizes up to 16 exabytes (16 million TB) and includes features like file compression, encryption (EFS), and disk quotas.
Some Linux distributions (like Ubuntu) offer a "Try before you install" mode. You can boot the entire OS from the USB drive, use it normally, and only commit to installing it on the hard drive when you are ready. It is a full desktop experience running entirely from USB.
Interactive Diagram
Launch the interactive diagram to see the OS installation process.
Open Interactive DiagramThe interactive diagram for this chapter demonstrates Installing an Operating System. It shows the full OS installation process from bootable USB to desktop, with partitioning and setup.
What to explore:
- click through each installation step; choose partition options; watch the progress bar as files are copied
- installing an OS involves creating bootable media, partitioning the drive, and copying system files to get a working computer
Knowledge Check
1. What is a bootable USB drive?
Answer: A USB drive formatted to boot a computer and run an OS installer
2. Which file system does Windows typically use for its main partition?
Answer: NTFS
3. What is the purpose of partitioning a drive during OS installation?
Answer: To divide the drive into logical sections, each functioning as a separate unit