Switching to Linux as my Daily Driver - (Part 1)
A step-by-step guide to safely install CachyOS alongside Windows in a dual-boot setup, with partitioning tips, EFI precautions, and guidance on how to reverse or remove it later.
I want to dual boot my Windows with a Linux system
You ask why? It looks much more fun and exploratory. This is not an article on why I am changing in detail or my journey to this decision. This is just documentation on the process to dual boot with my existing Windows. Yes, I know, I would still need Windows — it has a way of pulling you back in for one thing or the other.
Why CachyOS?
I picked CachyOS — a variant of Arch Linux. I have tried it on an external hard drive and I believe I can cope now.
Why Cachy? Well, they say it caches so it's faster. I partly agree but realized they played a trick on us.
The kernel is not complete. I couldn’t even use iptables
in the default kernel.
That won’t be a problem for many users, and switching kernels is part of the learning process.
You get a system you can tinker with and learn from.
The instruction below guides you through the dual boot installation. Disappointment alert: I generated this from ChatGPT — hopefully no hallucinations or dangerous assumptions.
🧭 What We’ll Cover
- Preparation inside Windows
- Bootable USB creation
- BIOS / Boot setup
- Safe partitioning
- Installation (CachyOS installer)
- GRUB + EFI handling
- Reversal / recovery (if you change your mind)
🧭 1️⃣ Prepare Windows
✅ Back up first
Back up your important files to the cloud or an external disk. We won’t touch Windows, but mistakes happen.
✅ Disable “Fast Startup”
Prevents NTFS locks that confuse Linux:
Control Panel → Power Options → Choose what the power buttons do → Change settings that are currently unavailable → Uncheck “Turn on fast startup” → Save.
✅ Disable BitLocker (if enabled)
If your drive is encrypted, suspend or disable BitLocker before partitioning.
✅ Shrink your Windows partition
Right-click Start → Disk Management → Right-click C: → Shrink Volume → Leave unallocated space.
💽 2️⃣ Create CachyOS USB
🧰 You’ll need:
- CachyOS ISO
- Rufus on Windows
⚙️ Rufus Settings:
- Device → your USB
- Boot selection → CachyOS ISO
- Partition scheme → GPT
- Target system → UEFI (non-CSM)
- Click Start
⚙️ 3️⃣ BIOS Settings (before boot)
Reboot → press F1 / F2 / F10 / F12 (depends on Lenovo) to enter BIOS.
- UEFI mode: Enabled (not Legacy/CSM)
- Secure Boot: Disabled
- Boot order: USB first
💾 4️⃣ Recommended Partition Sizes
Partition | Mount Point | Type | Size | Notes |
---|---|---|---|---|
EFI (existing) | /boot/efi | FAT32 | Already exists (~100–500 MB) | Do not delete — reuse it |
Root | / | ext4 or btrfs | 80–100 GB | OS, apps, updates |
Home | /home | ext4 or btrfs | 100–150 GB | User data |
Swap | swap | — | 4–8 GB | For suspend/hibernate |
Total suggestion: 200–250 GB for CachyOS, leaving plenty for updates and packages.
🧩 5️⃣ Install CachyOS
- Boot from the USB → choose “Boot CachyOS Installer”.
- If available, choose “Install alongside Windows Boot Manager.”
- If not, choose manual partitioning and use unallocated space.
- Select existing EFI partition (
/dev/nvme0n1p1
) → Mount point/boot/efi
→ Do not format. - Proceed — CachyOS will install GRUB and detect Windows automatically.
When done, reboot — you’ll see the GRUB menu with:
- CachyOS
- Windows Boot Manager
🪟 6️⃣ Post-install: Accessing Windows from Linux
sudo mkdir /mnt/windows sudo lsblk sudo mount /dev/nvme0n1p3 /mnt/windows
You can browse Windows files from your file manager and optionally set it to auto-mount in /etc/fstab
.
⚠️ 7️⃣ If You Change Your Mind Later
- Boot into Windows.
- Open Command Prompt (Admin) and run:
bcdedit /set {bootmgr} path \EFI\Microsoft\Boot\bootmgfw.efi
- Delete Linux partitions from Disk Management (right-click → Delete Volume).
- Optionally expand your Windows partition to reclaim space.
- To remove GRUB entry:
bcdboot C:\Windows
(or use EasyUEFI GUI tool)
The EFI entries are stored separately — removing GRUB or changing the default boot won’t break Windows.
🧠 8️⃣ Common Warnings
- ❗ Never format or delete the EFI partition — just reuse it.
- ❗ Install CachyOS in UEFI mode (same as Windows).
- ❗ Turn off Fast Startup & Hibernation in Windows — otherwise Linux mounts Windows read-only.
- ✅ Keep a Windows USB handy in case you ever need to repair boot.
No comments yet. Login to start a new discussion Start a new discussion