Linux (Ubuntu)
Getting Started · #3 of 19

Dual-Boot Installation

Ubuntu + Windows

Why Dual-Boot?

Dual-booting lets you keep Windows for gaming/specific software while learning Linux. At startup, you’ll see a menu to choose which OS to boot.

Prerequisites Checklist

Before you begin, complete these steps:

Creating Bootable USB with Rufus (Windows)

Rufus is a free, portable tool that creates bootable USB drives. No installation needed.

Step-by-Step:

  1. Download Rufus from rufus.ie (portable version, ~1MB)
  2. Insert USB drive (8GB minimum, will be completely erased)
  3. Launch Rufus — it auto-detects your USB drive
  4. Configure:
    • Device: Your USB drive should be auto-selected
    • Boot selection: Click “SELECT” and choose your Ubuntu ISO
    • Partition scheme: GPT (for UEFI) or MBR (for Legacy BIOS)
      • Modern PCs (2012+): Use GPT
      • Older PCs: Use MBR
    • File system: FAT32
    • Volume label: “UBUNTU” (optional)
  5. START — Rufus warns everything will be erased
  6. Wait 5-10 minutes — progress bar shows write status
  7. Done — Safe to eject when Rufus says “READY”

⚠️ WARNING: This will ERASE everything on the USB drive. Back up any files first!

Fun fact: Rufus is named after a dog, but it’s arguably more reliable than most pets at creating boot drives. It’s been creating bootable USBs since 2011.

Understanding Boot Keys

Getting into the boot menu can feel like a scavenger hunt. Here’s a cheat sheet:

Common Boot Keys by Manufacturer:

| Brand | Boot Menu | BIOS Setup | Notes | |-------|-----------|------------|-------| | Dell | F12 | F2 | Spam key during Dell logo | | HP | F9 or Esc | F10 | Some models use Esc | | Lenovo | F12 | F1 or F2 | ThinkPads may use Enter first | | ASUS | F8 or Esc | Del or F2 | ROG models often use F8 | | Acer | F12 | F2 | May need enabling in BIOS | | MSI | F11 | Del | Gaming laptops | | Gigabyte | F12 | Del | Motherboards |

Tip: When in doubt, spam all these keys repeatedly during the logo screen. Timing is finicky — too early doesn’t work, too late and you miss it.

Boot Menu vs BIOS Setup

Boot Menu (F12, F9, etc.)

BIOS Setup (F2, Del, etc.)

Typical Boot Menu:

┌──────────────────────────────────┐
│  Boot Device Selection            │
│                                   │
│  [1] Windows Boot Manager         │
│  [2] USB: SanDisk Cruzer 8GB   ← │ Select this
│  [3] UEFI: Built-in EFI Shell    │
│  [4] Enter BIOS Setup             │
│                                   │
│  Use ↑↓ to select, Enter to boot │
└──────────────────────────────────┘

Finding your boot key is like a scavenger hunt where the prize is installing Linux. Each manufacturer decided to be unique, naturally.

Shrinking Windows Partition

  1. Press Win + X → Disk Management
  2. Right-click your main partition (usually C:)
  3. Select “Shrink Volume”
  4. Enter amount to shrink (50000 MB = 50GB minimum)
  5. Click “Shrink” — this creates “Unallocated” space

Boot from USB

  1. Insert your Ubuntu USB drive
  2. Restart and enter BIOS/UEFI (usually F2, F12, Del, or Esc during boot)
  3. Disable Secure Boot (optional, but reduces issues)
  4. Set USB as first boot device
  5. Save and exit — Ubuntu installer should start

Partition Layout

When you select “Install Ubuntu alongside Windows,” the installer handles most of this. For manual partitioning:

Use the partition calculator below to plan your layout:

| Partition | Mount Point | Size | Type | Purpose | |-----------|-------------|------|------|---------| | EFI | /boot/efi | 512 MB | FAT32 | Bootloader (may already exist) | | Root | / | 25-50 GB | ext4 | Operating system and programs | | Swap | [swap] | RAM size | swap | Virtual memory, hibernation | | Home | /home | Remaining | ext4 | Your files (documents, config) |

Tip: If you have 16GB+ RAM, you can skip swap or make it smaller (4-8GB).

The Bootloader: GRUB

GRUB (GRand Unified Bootloader) is what shows you the OS selection menu at startup.

┌─────────────────────────────────────┐
│           GNU GRUB                   │
│                                      │
│   Ubuntu                             │
│   Advanced options for Ubuntu        │
│   Windows Boot Manager               │
│   System setup                       │
│                                      │
│  Use ↑↓ to select, Enter to boot    │
└─────────────────────────────────────┘

GRUB lives on the EFI partition and is installed automatically.

Post-Installation

After Ubuntu boots for the first time:

  1. Update the system:

    sudo apt update && sudo apt upgrade

  2. Install drivers (if needed): Settings → Additional Drivers

  3. Adjust boot order (optional): Default is Ubuntu. To change:

    sudo nano /etc/default/grub
# Change GRUB_DEFAULT=0 to GRUB_DEFAULT=2 for Windows
sudo update-grub

Troubleshooting

Windows not showing in GRUB?

sudo update-grub

Black screen after install?

Boot with nomodeset kernel parameter. In GRUB, press e, add nomodeset after quiet splash, press F10.

Clock is wrong in Windows?

Linux uses UTC by default. Fix:

timedatectl set-local-rtc 1

Partition Calculator

Enter your total disk space to get recommended partition sizes:

PartitionMountSizeTypePurpose