1. What is OS Installation?

Installing or flashing an Operating System (OS) means replacing the main software that controls the computer hardware.

Why Reinstall?

  • 🚀 Performance: Fix sluggishness.
  • 🦠 Security: Remove deep malware.
  • 🆕 Upgrade: Move from Win10 to Win11.
  • 🐧 Learning: Switch to Linux.

Common Scenarios

  • 💻 Buying a DOS/No-OS Laptop.
  • ☠️ Recovering from a crashed system.
  • 🛠️ Repurposing old hardware for servers.

2. Types of Operating Systems

Windows

Versions: 10, 11, Server.

Best for: Gaming, MS Office, Adobe, General Use.

Download from Microsoft Official Site.

Linux

Distros: Ubuntu, Kali, Mint, Fedora.

Best for: Coding, Hacking, Servers, Old PCs.

Download from Official Distro Sites.

Others

ChromeOS Flex: Cloud-based.

Hackintosh: macOS on non-Apple PC (Hard).

BSD: Advanced networking.

3. Prerequisites

Hardware

  • USB Drive: 8GB+ (Linux), 16GB+ (Windows).
  • Working PC: To download files.
  • Power: Plug in laptop charger!

Data

  • ⚠️ BACKUP: Installation can wipe drives.
  • Internet: Stable connection for 5GB+ downloads.

4. Downloading the ISO

An ISO file is a digital image of the installation disk. You don't just copy it to USB; you must flash it.

For Windows

1. Go to Microsoft Download page.

2. Download Media Creation Tool.

3. It automatically downloads & flashes USB.

For Linux

1. Go to Ubuntu/Kali website.

2. Download the .ISO file.

3. Use Rufus to flash it.

5. Flashing with Rufus (The Tool)

Rufus is the industry standard for creating bootable USBs.

1

Select Device

Plug in your USB and select it in Rufus.

2

Select Boot

Click "SELECT" and find your downloaded .ISO file.

3

Partition Scheme

GPT for UEFI (Modern).

MBR for Legacy BIOS (Old).

4

Start

Click START. Warning: USB data will be erased.

6. Booting from USB

Computers boot from Hard Disk by default. We must change this.

Method A: Boot Menu

Tap F12 / ESC / F10 / F9 immediately after power on.

Select your USB Name from the list.

Method B: BIOS Setup

Enter BIOS (F2/Del). Go to Boot tab.

Move USB to Priority #1.

7. The Installation 🛠️

Windows Steps

  1. Click "Install Now".
  2. Select "I don't have a product key".
  3. Choose Edition (e.g., Win 11 Pro).
  4. Select Custom Install.
  5. Delete old partitions (Clean Install).
  6. Select Unallocated Space -> Next.

Linux Steps

  1. Select "Try or Install".
  2. Choose "Erase disk" (Clean) OR "Install alongside" (Dual Boot).
  3. Create Username/Password.
  4. Wait for file copying.

8. Essential Post-Install Tasks

1. Drivers

Video, WiFi, Audio. Download from Laptop Manufacturer site.

2. Updates

Run Windows Update or sudo apt update.

3. Ninite

Use Ninite.com to install Chrome, VLC, Zoom in one go.

Advanced Concepts

BIOS vs UEFI

BIOS (Legacy): Old, uses MBR. 2TB limit.

UEFI: Modern, uses GPT. Secure Boot. Faster.

Partitions

EFI: Boot files.

Recovery: Repair tools.

Primary: Your C: Drive.