Dual booting Windows and Linux lets you run both on the same machine. Pick which one to boot when you start up. I've done this on three different laptops over the years and the process gets cleaner with every new release of both systems.
Heads up – this involves partitioning your drive, which always has a small chance of data loss if you mess up. Back up everything important first. Done? Good. Let's go.
Pick a Linux distribution
For beginners, Ubuntu is the easiest because it has the best Windows dual-boot support out of the box. Linux Mint is also great and feels closer to Windows visually. Pop!_OS is good if you have an NVIDIA GPU since it ships with the drivers preinstalled.
Download the ISO file from the official site of whichever distro you pick. The file is usually 3-5 GB.
Create a bootable USB
You need a USB drive with at least 8 GB of space. Download Rufus on Windows (it's free). Open Rufus, plug in the USB, pick the ISO file you downloaded, and click Start. Takes about 10 minutes.
Rufus warns that it'll wipe the USB. That's normal. Just pick OK. When it finishes, you have a Linux installer on the USB.
Make space for Linux on your Windows drive
In Windows, open the Start menu and search for Disk Management. Right-click your Windows C: partition and pick Shrink Volume. Reduce it by however much space you want for Linux – I usually go with 50 to 100 GB.
The unallocated space that's created is where Linux will go. Don't format it – leave it as unallocated. The Linux installer handles partitioning later.
Disable Fast Startup and Secure Boot
Windows' Fast Startup feature locks the disk in a way that can corrupt the file system when Linux mounts it. Turn it off:
- Open Control Panel and search for "power"
- Click Choose what the power buttons do
- Click Change settings that are currently unavailable
- Uncheck Turn on fast startup and save
For Secure Boot, restart the computer and press F2, F10, F12, or Delete during boot to enter BIOS. Each manufacturer uses a different key. Find the Secure Boot setting and disable it.
Boot from the USB and install Linux
Restart your computer with the USB plugged in. Mash the boot menu key (usually F12 or F8). Pick your USB drive from the list. The Linux installer loads.
During installation, when it asks how to set up the disk, pick Install Linux alongside Windows Boot Manager (or similar wording). This option uses the unallocated space you created and leaves Windows intact.
Do not pick "Erase disk and install Linux" – that wipes Windows. Read the option text carefully before clicking continue.
Set up your user and finish
Pick your timezone, keyboard layout, and create a username and password. The installer copies files for 10-20 minutes. When it finishes, restart and remove the USB when prompted.
On the next boot, you should see the GRUB menu – a black screen listing Ubuntu (or your distro), Windows Boot Manager, and a few other options. Use arrow keys to pick which one to boot. Default is Linux. You have a few seconds before it auto-selects.
Boot directly into Windows instead
If you want Windows as the default, you can change GRUB's default selection. Open a terminal in Linux and edit /etc/default/grub as root. Find the line GRUB_DEFAULT=0 and change it to the menu position of Windows (usually 2 or 3). Save, then run sudo update-grub.
Next reboot, Windows boots by default if you don't press any key during the GRUB countdown.
Windows shows wrong time after dual boot?
Linux and Windows handle the BIOS clock differently. Linux assumes UTC. Windows assumes local time. After dual booting, your Windows clock might be off by several hours.
Fix it from Linux. Open a terminal and run timedatectl set-local-rtc 1 –adjust-system-clock. That tells Linux to also use local time, matching Windows' behavior. Both systems now agree.
What hardware are you dual booting on? Mention your laptop model in the comments if anything weird happens during install – I'll mention known issues if I've seen them.