How to Install Linux Alongside Windows (Dual Boot)
Keep Windows and add Linux on the same machine: back up, shrink the Windows partition, install into the free space and pick a system at every boot — with clear size guidance and how to undo it later.
You want to try Linux, but you do not want to give up Windows: maybe you need some program that only works there, or you simply do not dare to take the full leap yet. The good news is you do not have to choose. It is called dual boot: having both systems installed at once on the same computer, and deciding which one to use every time you switch it on.
Done carefully — and this article is written so you do it carefully — it is a safe process. The real risk is not "using two systems at once"; it is rushing the partitioning step without having made a backup first. That is exactly what we are going to avoid.
The plain-language explanation
Right now, your hard drive or SSD is like a wardrobe with a single compartment: all of Windows lives inside it. What we are going to do is divide that wardrobe into two separate compartments (this is called partitioning): Windows stays in its own, exactly as it is, and we create a new, empty one for Linux. Each system only sees and uses its own compartment — they do not mix or step on each other.
A program called the boot manager (the most common one is GRUB) is what asks you, every time you turn on the computer, which of the two you want to open today. You do not have to install it separately — Linux installs it on its own, as part of the process.
Dual boot, virtual machine or live USB?
Before partitioning anything, it is worth confirming that dual boot is really what you need:
| Method | Main advantage | When to choose it |
|---|---|---|
| Dual boot | Full performance, no limits | You will use Linux regularly |
| Virtual machine | No touching partitions, Windows stays as is | You just want to try it, or use both at once |
| Live USB | Installs nothing on the disk | You want to try it for an afternoon, no commitment |
If after seeing this table what interests you is trying Linux without installing anything, you do not need to keep reading this article — a live USB (the same one you prepare for installing, but choosing "Try" instead of "Install") is enough. The rest of this guide is for those who already know they want real dual boot.
At a glance, this is the whole process:
Back up your data
The only step that is not optional under any circumstances.
Prepare the Linux USB
With Rufus or balenaEtcher, as in any installation.
Shrink the Windows partition
To leave free space, without deleting anything there.
Install Linux into the free space
The installer itself detects it and offers it as an option.
Choose which system boots
A menu will ask you every time you switch on the machine.
1. Make a backup
Warning: you are going to modify the partitions of the disk where Windows lives. The probability of something going wrong while following this guide calmly is low, but it is not zero — and an error in this particular step can affect your files. Before continuing, make a backup of your documents, photos and anything you cannot afford to lose. This step is not negotiable, even if everything else goes well.
2. Prepare a Linux installation USB
You need a USB stick of at least 8 GB, prepared with the installer of the distribution you have chosen. If you do not yet know which one to install, our guide on which Linux distribution to choose helps you decide before going on. The process of preparing the USB itself is explained step by step in how to create a bootable USB — we do not repeat it here to avoid duplication, but it is exactly the same process.
3. Shrink the Windows partition to make room
Type "Disk Management" in the Windows search box (Windows key) and open it. Right-click your main partition (usually "C:") and choose "Shrink Volume". Windows will calculate the maximum space it can free without touching your files — you only have to say how much you want to reserve for Linux.
Tip: as a clear reference (not the usual "it depends", which is the most repeated and least helpful answer): 60 GB is a comfortable starting point for normal use with Linux Mint or Ubuntu — enough for the system, updates and several programs, without running short right away. If you will only use it for light tasks, 40 GB also works. Less than that, and you can easily run out of space soon.
That space will be marked as "Unallocated" — it does not belong to any system yet. It is precisely the gap where we will install Linux in the next step.
4. Install Linux into the space you freed
Restart the computer with the USB plugged in and enter the boot
menu (usually by pressing F12, F2 or
Del at power-on — it varies by manufacturer). Choose the
USB as the boot device.
Follow the Linux installer normally until you reach the "Installation type" step. There you will see an option similar to "Install [your distro] alongside Windows Boot Manager" — that is the one you want. The installer automatically detects the space you freed in the previous step and uses it without touching the Windows partition.
Note: if your computer has Secure Boot enabled (a protection in the BIOS/UEFI that only lets "verified" software boot) and the installer does not start, you may have to disable it from the BIOS. Ubuntu and several modern distros are compatible with Secure Boot enabled, so first try without touching anything — only disable it if the installer plainly refuses to boot.
5. Choose which system boots each time
When the installation finishes and you restart, a menu (GRUB) will appear with a list: your Linux distribution, and "Windows Boot Manager". Use the arrow keys to choose and press Enter. If you do not touch anything, the default option will boot after a few seconds — usually Linux, although this can be changed later if you prefer it to be Windows.
Done: if you got this far and the menu lets you choose between the two systems, dual boot is working correctly. Try booting each one at least once to confirm both run fine before considering the process fully finished.
With both systems now running, it is common to want to move files from one to the other — the good news is that, being on the same disk, it is simpler than it looks. We explain it in how to share files between Linux and Windows. And if your freshly installed Linux ever freezes right when logging in with your user, we have a specific guide on Linux freezing at login.
What if I want to remove Linux later?
It can be done without harming Windows, as long as the right order is followed: first delete the Linux partition from Windows "Disk Management", and then repair the Windows boot loader (which, after deleting the Linux partition, may be left pointing at a system that no longer exists). We do not detail it step by step here because it deserves its own full guide — the key is not to simply delete the Linux partition and expect Windows to boot on its own, because it usually will not without that second step.
Frequently asked questions
Will I lose my Windows files by doing this?
No, if you follow the order in this guide: shrinking the Windows partition does not delete any file, it only frees unused space. The real risk only appears if the backup step is skipped and something goes wrong — that is why it is not optional.
Which of the two systems boots by default?
Whichever is marked as default in the GRUB menu after installation, usually Linux. It can be changed later from within Linux if you prefer Windows to be the one that boots on its own when you touch nothing.
Can I remove Linux later without breaking Windows?
Yes, as long as it is done in the right order: first delete the Linux partition, then repair the Windows boot loader. Doing it the other way round, or only the first step, is the most common reason Windows stops booting after removing Linux.
Do I need to disable the Windows antivirus for this?
No. Dual boot does not require disabling any Windows protection. The only thing that sometimes needs checking is Secure Boot in the BIOS, and only if the Linux installer fails to start at all.
Does dual boot make Windows slower?
No. Each system uses its own partition and only the one you choose to boot is loaded into memory — the other is simply untouched in the meantime. The only noticeable difference is having less free disk space, having split it between the two.