Installing a second operating system on a laptop: from choosing an OS to setting up multiboot

Installing a second operating system on a laptop is a task that scares many users. In fact, the process is no more complicated than reinstalling the main OS, but it requires care at the stage of disk partitioning and bootloader configuration. In this article we will look at all the nuances: from choosing a compatible operating system to solving typical problems after installation.

The main reasons for installing a second OS on a laptop are testing new software, working with specialized programs (for example, Linux-versions AutoCAD or Blender), studying IT technologies or simply wanting to try an alternative Windows 11 without giving it up. It is important to understand that the process is different for laptops with UEFI and outdated BIOS, as well as for devices with macOS (where required Boot Camp or virtualization).

We will not limit ourselves only Linux — consider options with Windows 10/11 as a second system ChromeOS for weak laptops, and even Hackintosh (macOS on non-Apple hardware). We will pay special attention disk partitioning without data loss and configuration GRUB or Windows Boot Manager for correct OS selection at boot.

1. Choosing a second operating system: what to install on a laptop

The first step is to decide which OS you want to install in parallel with the main one. There are several criteria: compatibility with laptop hardware, purpose of use and level of your technical training.

For most users, the best options are:

• 🐧 Linux distributions (For example, Ubuntu, Fedora, Linux Mint) are free, lightweight and suitable for programming, server tasks or data recovery. Modern distributions automatically detect hardware and offer a simple installer with disk partitioning.
• 🪟 Windows 10/11 - relevant if the main system Linux or macOS, but you need specific programs like 1C, Adobe Photoshop or games via Steam. Requires a license and more disk space (minimum 30–40 GB).
• 🍎 macOS (Hackintosh only) - suitable for owners of laptops with processors Intel (up to 12th generation) or AMD Ryzen (with restrictions). Difficult to set up, Wi-Fi/Bluetooth may not work without additional drivers.
• ☁️ ChromeOS — a lightweight system for weak laptops (for example, Acer Chromebook or old Lenovo ThinkPad). Suitable for web surfing and Android-applications.

Check before choosing hardware requirements on the official website of the OS. For example, Windows 11 requires TPM 2.0 And Secure Boot, and some Linux-distributions (like Arch Linux) are not suitable for beginners due to the complexity of installation. For laptops with NVIDIA Optimus (hybrid graphics) it is better to choose distributions that support Prime (For example, Ubuntu 22.04+ or Manjaro).

2. Preparing the laptop: backup and disk partitioning

The most critical part of the process is disk partitioning. An error at this stage may result in data loss or the inability to boot the main system. Let's start with preparation:

1. Back up your important data. Even if you are confident in your actions, use an external drive or cloud (Google Drive, Yandex Disk). This is especially true for laptops with a single disk (C:), where you have to compress the partition.
2. Check free space. The second OS will require a separate partition:
   • 📁 Linux: minimum 20 GB (optimally 50+ GB if you plan to install programs).
   • 📁 Windows 10/11: 30 GB minimum (60+ GB recommended, including updates).
   • 📁 macOS: 50+ GB (due to large system file size).

To partition a disk without losing data, use the built-in tools:

• 🪟 B Windows: Disk management → select a drive (for example, C:) → Shrink Volume. Enter the size in megabytes (1 GB = 1024 MB). After compression, unallocated space will appear.
• 🐧B Linux: use GParted (install via sudo apt install gparted in Ubuntu/Debian).
• 🍎 On macOS: open Disk Utility → select drive → Break into sections.

⚠️ Attention: If your laptop has BitLocker (disk encryption in Windows Pro/Enterprise), first turn it off in Control Panel → BitLocker Drive Encryption. Otherwise, after changing the partitions, the system will require a recovery key.

3. Creating a bootable USB flash drive and setting up BIOS/UEFI

To install a second OS, you will need a bootable drive. We recommend using a USB flash drive with a capacity of at least 8 GB (for Windows 11 - 16 GB).

Ways to create a bootable USB flash drive:

sudo dd if=путь/к/файлу.iso of=/dev/sdX bs=4M status=progress

sudo /Applications/Install\ macOS\ Ventura.app/Contents/Resources/createinstallmedia --volume /Volumes/MyUSB

After creating a flash drive, you need to configure loading from it into BIOS/UEFI:

1. Reboot your laptop and enter the BIOS by clicking:
   • Lenovo: F2 or Fn + F2
   • HP: Esc → F10
   • Dell: F12
   • Asus: Del or F2
   • Acer: F2 or Ctrl + Alt + Esc

4. Installing a second OS: step-by-step instructions for Windows and Linux

The installation process depends on the operating system you select. Let's look at the two most popular scenarios: installation Linux next to Windows And Windows 10/11 as a second system.

4.1. Installing Linux (Ubuntu, Mint, Fedora) next to Windows

Most Linux-distributions offer a simple graphical installer with automatic multiboot setup.

1. Boot from flash drive and select Try Ubuntu (or an equivalent for your distribution) to test the system before installation.
2. Run the installer and follow the instructions until the disk partitioning step. Select Install next to Windows Boot Manager (or Another option for manual settings).
3. Manual marking (recommended):
   • 📍 /boot: 500 MB (partition ext4, mount point /boot).
   • 📍 swap: equal to the amount of RAM (if RAM ≤ 8 GB) or 2–4 GB (if RAM ≥ 16 GB).
   • 📍 / (root partition): all remaining space (ext4).

4.2. Installing Windows 10/11 as a second system

If the main system is Linux or macOS, installation process Windows more difficult due to the characteristics of the bootloader.

1. Boot from flash drive and on the installation screen click Shift + F10to open the command prompt.
2. Manual disk partitioning:

   diskpart
   list disk
   select disk 0
   list partition
   select partition X  (выберите нераспределённое пространство)
   create partition primary size=102400 (размер в МБ)
   format fs=ntfs quick
   assign letter=W
   exit

3. Continue installationby selecting the created section. After completion Windows will overwrite the bootloader, and Linux will stop loading.
4. Repair GRUB via Live CD Linux:

   sudo add-apt-repository ppa:yannubuntu/boot-repair
   sudo apt update
   sudo apt install boot-repair
   boot-repair

sudo os-prober
sudo update-grub

5. Setting up multiboot: GRUB, Windows Boot Manager and rEFInd

After installing the second OS, you need to configure the bootloader so that when you turn on the laptop, a selection menu appears. Default Linux uses GRUB, and Windows — Windows Boot Manager. Let's consider the options:

GRUB (for Linux + Windows):

• 🔧 To change the OS order in the menu, edit the file /etc/default/grub (need rights sudo):

  GRUB_DEFAULT=0  (0 — первая ОС в списке, 1 — вторая и т. д.)
  GRUB_TIMEOUT=10  (время ожидания в секундах)

• 🔧 After changes, execute sudo update-grub.

Windows Boot Manager (if the main system is Windows):

• 🔧 Open msconfig (click Win + R, enter msconfig) → tab Loading. Here you can change the OS order and timeout.
• 🔧 To add Linux in the menu Windows use EasyBCD (free version).

rEFInd (alternative bootloader for UEFI):

• 🌟 Install from repositories Linux:

  sudo apt install refind  (Debian/Ubuntu)
  sudo refind-install

• 🌟 For Windows download rEFInd with official website and run install.sh from under Linux or macOS.

6. Typical problems and their solutions

Even with proper installation, problems may arise. Let's look at the most common ones and how to solve them:

sudo update-grub

sudo ubuntu-drivers autoinstall  (Ubuntu)
sudo dnf install broadcom-wl  (Fedora)

sudo apt install tlp tlp-rdw
sudo systemctl enable tlp

⚠️ Attention: If after installation Windows 11 on a laptop with Linux time at Linux goes astray, turn it off Windows automatic time synchronization:

1. Open Control Panel → Date and Time → "Internet Time" tab.
2. Click Change settings and uncheck Synchronize with an Internet time server.
3. B Linux execute timedatectl set-local-rtc 1.

7. Optimizing the operation of two systems on one laptop

To keep the two operating systems from interfering with each other, follow these guidelines:

Data separation:

• 🗃️ Create a separate section NTFS or FAT32 for sharing files between OS. B Linux it will be mounted automatically, in Windows will appear as an additional drive.
• 🗃️ Use cloud services to synchronize documents (Google Drive, Dropbox) or Nextcloud on your home server.

Download management:

• ⚡ To speed up loading, reduce the timeout in GRUB (open /etc/default/grub and change GRUB_TIMEOUT=3).
• ⚡ B Windows turn off Quick start (Control Panel → Power Options → What the Power Buttons Do) to Linux mounted correctly NTFS-sections.

Energy saving:

• 🔋 B Linux install TLP (see section 6) and disable unnecessary services:

  sudo systemctl disable bluetooth.service  (если не используете)

• 🔋 B Windows select power plan Balanced and turn off background applications in Settings → Privacy → Background apps.

Security:

• 🔒 Encrypt your home partition in Linux (ext4 with LUKS) and turn it on BitLocker for Windows-section.
• 🔒 Use different passwords for each OS and customize firewalld (Linux) or Windows Defender.

FAQ: Frequently asked questions about installing a second OS