How to Dual Boot Windows 10 and Arch Linux Safely (2025 Guide)

If you love Windows 10 but also want the power of Arch Linux, dual-booting is the best of both worlds. You can switch between Windows for gaming and Arch for coding.

In this blog, I'll walk you through how to safely install Arch Linux alongside Windows 10, covering BIOS/UEFI setup, partitioning, and GRUB bootloader installation.

What You'll Need

• A USB drive (at least 4GB)
• Windows 10 already installed
• Internet connection
• Arch Linux ISO from the official site
• A tool like Rufus or Balena Etcher

Step 1: Prepare Windows for Dual Boot

1. Backup your data. Always first.
2. Disable Fast Startup & Hibernation:

   powercfg /h off
   

Then go to Control Panel →’ Power Options →’ Choose what power buttons do and uncheck "Turn on fast startup." 3. Shrink Windows Partition: - Press Win + X →’ Disk Management. - Right-click your main drive (C:) and select Shrink Volume. - Leave at least 40GB free for Arch Linux. You'll see unallocated space.

Step 2: Create a Bootable Arch Linux USB

Use Rufus (on Windows):

• Select your USB and Arch ISO.
• Set Partition scheme to GPT (for UEFI) or MBR (for BIOS).
• File System →’ FAT32.
• Click Start.

Step 3: Boot Into Arch Linux Installer

1. Restart your PC and enter BIOS/UEFI (press F2, Del, or Esc).
2. Disable Secure Boot.
3. Set your USB as the first boot device.
4. Boot and choose Boot Arch Linux (x86_64) from the menu.

Step 4: Connect to the Internet

• Ethernet: ping archlinux.org (should work automatically).
• Wi-Fi: Use iwctl to connect.

Step 5: Partition the Disk

Run lsblk to find your drive (e.g., /dev/sda). We'll use cfdisk:

cfdisk /dev/sda

Choose GPT (if UEFI). Now create:

1. EFI partition (if UEFI): 512MB, Type: EFI System.
2. Root partition (Linux): Use the unallocated space. Type: Linux filesystem.
3. (Optional) Swap: 2—4GB, Type: Linux swap.

Write changes and quit.

Step 6: Format Partitions

• UEFI: mkfs.fat -F32 /dev/sda1
• Root: mkfs.ext4 /dev/sda2
• Swap (if made): mkswap /dev/sda3 and swapon /dev/sda3

Step 7: Mount the Partitions

mount /dev/sda2 /mnt
mkdir /mnt/boot
mount /dev/sda1 /mnt/boot

Step 8: Install Base System

pacstrap /mnt base linux linux-firmware vim networkmanager

Generate fstab:

genfstab -U /mnt >> /mnt/etc/fstab

Step 9: Chroot Into the System

arch-chroot /mnt

• Set timezone: ln -sf /usr/share/zoneinfo/Asia/Karachi /etc/localtime and hwclock --systohc
• Set locale: Edit /etc/locale.gen, uncomment en_US.UTF-8, run locale-gen, and echo "LANG=en_US.UTF-8" > /etc/locale.conf.
• Set hostname & password: echo "archpc" > /etc/hostname and passwd.

Step 10: Install GRUB Bootloader

For UEFI systems:

pacman -S grub efibootmgr os-prober
grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id=Arch
os-prober
grub-mkconfig -o /boot/grub/grub.cfg

For Legacy BIOS systems:

pacman -S grub os-prober
grub-install /dev/sda
os-prober
grub-mkconfig -o /boot/grub/grub.cfg

GRUB should detect your Windows Boot Manager automatically.

Step 11: Enable Network and Exit

systemctl enable NetworkManager
exit
umount -R /mnt
reboot

Remove the USB when prompted.

Step 12: Boot Menu (Choose OS)

On reboot, you'll see the GRUB menu with options for "Arch Linux" and "Windows Boot Manager."

Troubleshooting Tips

• GRUB doesn't show Windows: Run sudo os-prober then sudo grub-mkconfig -o /boot/grub/grub.cfg.
• Boots directly into Windows: Go into BIOS and set "Arch/GRUB" as the first boot option.
• Arch doesn't boot: Use a live USB, arch-chroot into your system, and reinstall GRUB.

Final Thoughts

Dual-booting Windows 10 and Arch Linux gives you the power to enjoy both ecosystems. If you follow this guide carefully, you'll have a smooth dual-boot setup with zero data loss.