How to Dual-Boot Windows 11 and Linux Mint Safely

Dual-booting Windows 11 and Linux Mint on one drive is the cheapest upgrade most PCs will ever get. No second machine, no virtual machine overhead, no swapping cables. You reboot, pick a system from a menu, and the hardware is fully yours either way.

The catch is that it all happens on a single disk, and partitioning mistakes are unforgiving. The good news: if Windows 11 is already installed and your machine uses UEFI firmware, the process is mostly preparation, one guided installer, and a couple of small fixes afterwards. Order matters. Windows first, Linux second, always.

Before You Start: Backups, Firmware, and Fast Startup

Do not skip this section. Resizing a partition is a routine operation, but it is still an operation on the only copy of your data.

• Back up anything you cannot recreate. An external drive with your documents, photos and project folders is enough for most people. If you have room for a full disk image, even better.
• Free up space in Windows. Mint itself is small, but you will want room to breathe. A 60 GB slice is a sensible minimum; 100 GB or more if Linux will be your daily driver.
• Check your firmware mode. Press Windows + R, type msinfo32 and look at BIOS Mode and Partition Style. You want UEFI and GPT. If it says Legacy and MBR, the steps below still work, but the bootloader details differ.
• Turn off Fast Startup. In Control Panel, go to Power Options, then "Choose what the power buttons do", then "Change settings that are currently unavailable", and clear "Turn on fast startup". This setting leaves the Windows filesystem half-awake, and Linux writing to it can corrupt data.
• Deal with BitLocker or Device Encryption. If it is on, back up your recovery key first and suspend protection before resizing. Trying to modify an encrypted partition while it is locked is a bad afternoon.

Pick a Layout: Simple or Room to Grow

Two layouts cover almost everyone. The simple one gives Linux a single partition for everything, mounted at the root of the filesystem, written as /. Your Windows drive stays mounted from Linux when you need to grab a file. It's quick and Mint's installer can do it automatically.

The flexible one splits Linux into two partitions: / for the system and /home for your personal files. That way, when you upgrade to a newer Mint release or reinstall, your documents, settings and browser profiles stay exactly where they are. It costs nothing extra and I'd recommend it if you have the space.

Either way, both systems share one small EFI System Partition that already exists on your drive. Do not delete it, do not format it, and do not create a second one.

Shrink Windows and Leave the Space Unallocated

1. Open Disk Management: press Windows + X and choose Disk Management, or run diskmgmt.msc.
2. Right-click your C: drive and choose Shrink Volume. Windows will report how much it can give up.
3. Enter the amount you want for Linux, in megabytes, and confirm. A 100 GB slice is 102400 MB.
4. If Windows offers far less than you expect, it's usually blocked by the hibernation file or page file. Open an administrator Command Prompt and run powercfg /h off, then try again. You can turn hibernation back on later with powercfg /h on.
5. If it still refuses, boot the Mint USB and use GParted from the live desktop to resize the NTFS partition. It's slower and less polite about it, but effective. Never interrupt the operation, and keep the machine plugged in.

The result you want is a block of unallocated space next to your Windows partition. Do not create a new NTFS volume there "to reserve it" — the Linux installer needs unallocated space, not a formatted one.

Build the Linux Mint USB Stick

Download the ISO from the official Linux Mint site and check its SHA-256 hash before you trust it. On Windows, open a terminal in the download folder and run certutil -hashfile linuxmint.iso SHA256, then compare with the value published alongside the download.

Write the ISO to an 8 GB or larger USB stick with Rufus or balenaEtcher. Rufus will ask about partition scheme; choose GPT and UEFI target if that option appears. Everything on the stick gets erased, so use one you don't need.

Reboot and open your boot menu — usually F12, F10, F9 or Esc, depending on the manufacturer. If the USB doesn't show up, temporarily disable Secure Boot in your firmware settings. Mint's bootloader is signed and generally works with Secure Boot enabled, but some firmware is picky about third-party entries. You can switch it back on once installation is finished.

Install Mint Alongside Windows

Boot the USB and pick Start Linux Mint. The live desktop is the full system running from the stick, so you can safely poke around before committing to anything.

Start the installer. Connect to Wi-Fi when asked — the option to install multimedia codecs needs it. Then you reach the crucial screen, "Installation type".

If you chose the simple layout, select Install Linux Mint alongside Windows Boot Manager. The installer will shrink nothing, use the unallocated space, and reuse the existing EFI partition. It is the low-risk path, and it works well.

If you want the separate /home layout, choose Something else and build it by hand. Select the free space and create:

• Root partition: ext4, mount point /, around 50 GB, format it.
• Home partition: ext4, mount point /home, the rest of the space, format it.
• EFI partition: the small existing FAT32 partition, usually 100–500 MB. Set it to use as EFI System Partition and do not tick format.

Leave "Device for bootloader installation" at its default, the whole disk rather than a partition. Before you click install, read the summary twice and confirm the disk size matches the drive you meant. On a two-drive machine, the installer sometimes defaults to the wrong one.

First Boot: Boot Order, Clocks, and NTFS Access

When it finishes, remove the USB and reboot. GRUB should appear with Linux Mint and a Windows Boot Manager entry. If Windows starts instead, fix the order in your firmware setup or run efibootmgr -v from Mint to see and reorder the entries.

Two small things are worth fixing on day one. First, the clock: Linux stores hardware time as UTC, Windows as local time, so one system will show the wrong hour. Run timedatectl set-local-rtc 1 in Mint to match Windows. Second, your Windows files are available under /media/yourname/ once you click the drive in the file manager. Writing to them only works safely if Windows was fully shut down — one more reason Fast Startup stays off.

A Few Habits That Keep a Dual-Boot Machine Healthy

Set up Timeshift on the Linux side and let it keep a few snapshots. It rolls back a broken update in minutes and has saved plenty of installs. Keep at least 10–15 percent of each partition free; both systems slow down and get temperamental when they run out of room.

Windows feature updates occasionally reset the boot order, though with UEFI they rarely damage GRUB. If the menu disappears, boot the Mint USB, run sudo update-grub, and you're usually back in business. Keep that stick around — it doubles as your rescue kit.

Then just use it. Boot into Mint when you want a quiet, fast machine that does what you tell it. Boot into Windows when a specific piece of software demands it. That's the whole point.

Photo: Tima Miroshnichenko / Pexels