--- title: "How To Dual Boot Windows and Install Ubuntu on a Partition" description: "Discover dual-booting operating systems and install Ubuntu on a Partition to switch between Windows and Linux as needed!" canonical: "https://adamtheautomator.com/install-ubuntu-on-a-partition/" --- # How To Dual Boot Windows and Install Ubuntu on a Partition > Discover dual-booting operating systems and install Ubuntu on a Partition to switch between Windows and Linux as needed! Source: https://adamtheautomator.com/install-ubuntu-on-a-partition/ --- ATA Learning Tap to hide [ ATA Learning ](/) * [Home](/) * [Tutorials](/tutorials/) * [Instructors](/author/) * [Advertising](/advertising/) * [Recommended Resources](/resources/) * [About Adam](/about-adam/) Search for: * [](https://twitter.com/adbertram) * [](https://github.com/Adam-the-Automator) * [](https://www.linkedin.com/company/adam-the-automator-llc) * [](/feed/) ![How To Dual Boot Windows and Install Ubuntu on a Partition](https://adamtheautomator.com/wp-content/uploads/2022/08/How-To-Dual-Boot-Windows-and-Install-Ubuntu-on-a-Partition.jpg) # How To Dual Boot Windows and Install Ubuntu on a Partition [![](https://secure.gravatar.com/avatar/1bc5e1d52466fc3739f550c8d78be310684747bf1466a98d698320627ea243e2?s=192&d=mm&r=g)Michael Nguyen Tu](https://adamtheautomator.com/author/michael-nguyen-tu/)31 August 20228 min. read Categories: [IT Ops](/category/it-ops/) Tags:[Ubuntu Linux](/tag/ubuntu-linux/)[Windows](/tag/windows/) Table of Contents * [Prerequisites](#prerequisites) * [Preparing a Bootable USB](#preparing-a-bootable-usb) * [Disabling Secure Boot](#disabling-secure-boot) * [Booting to USB and Install Ubuntu on a Partition Alongside Windows 10](#booting-to-usb-and-install-ubuntu-on-a-partition-alongside-windows-10) * [Dual-Booting to Ubuntu and Windows](#dual-booting-to-ubuntu-and-windows) * [Troubleshooting a Missing “Install Ubuntu alongside Windows Boot Manager” Option](#troubleshooting-a-missing-install-ubuntu-alongside-windows-boot-manager-option) * [You Created a Formatted Partition Instead of Free Space](#you-created-a-formatted-partition-instead-of-free-space) * [Fast Startup Left the Windows Partition Dirty](#fast-startup-left-the-windows-partition-dirty) * [The SATA Controller Runs in Intel RST or RAID Mode](#the-sata-controller-runs-in-intel-rst-or-raid-mode) * [The USB Booted in Legacy Mode but Windows Uses UEFI](#the-usb-booted-in-legacy-mode-but-windows-uses-uefi) * [Falling Back to Manual Partitioning](#falling-back-to-manual-partitioning) * [Conclusion](#conclusion) Do you have a Windows 10 computer and want to dual boot Ubuntu to take advantage of the best of both worlds? You are in luck. This guide will show you how to install Ubuntu on a partition alongside Windows 10. Are you excited yet? Read on and get started! ## Prerequisites This tutorial will be a hands-on demonstration. If you’d like to follow along, be sure you have the following. * A Windows 10 machine with enough free storage space that you can spare 20GB for the Ubuntu partition. * A USB flash drive with at least 4GB of free storage. This tutorial assumes that you have already plugged this flash drive into the computer. * An Ubuntu ISO file that you want to install. This tutorial uses Ubuntu 20.04 Desktop. ## Preparing a Bootable USB Now that you have all the prerequisites, you can prepare a bootable USB drive containing the Ubuntu installation files. There are a few different ways to create a bootable USB drive, but for this tutorial, you will use the free and open-source utility called _Rufus_. This tool is a lightweight utility with an intuitive interface. 1\. First, check whether your computer’s motherboard is [BIOS (Legacy) or UEFI](https://www.partitionwizard.com/partitionmagic/uefi-vs-bios.html). Press WIN+R to open the Run dialog, type msinfo32, and press Enter. Confirm whether the BIOS Mode is Legacy or UEFI. In this example, the computer has UEFI. ![Check the computer BIOS or UEFI](https://adamtheautomator.com/wp-content/uploads/2022/08/image-491.png) Check the computer BIOS or UEFI 2\. Open a browser and open the [Rufus website](https://rufus.ie/en/). Scroll to the Download section and click the first link to download the latest version of Rufus. At this time of writing, the newest version is _3.20_. ![Download Rufus](https://adamtheautomator.com/wp-content/uploads/2022/08/image-492.png) Download Rufus 3\. After downloading, locate the file and run it. ![Locate and run Rufus](https://adamtheautomator.com/wp-content/uploads/2022/08/image-493.png) Locate and run Rufus You’ll see the Rufus main window, similar to the screenshot below. ![Rufus application main window](https://adamtheautomator.com/wp-content/uploads/2022/08/image-494.png) Rufus application main window 4\. Under the Drive Properties section, click the Device dropdown and choose the USB flash drive you’ll flash. If you only have one USB flash drive connected, that device will already be the default selection. ![Select the USB flash drive](https://adamtheautomator.com/wp-content/uploads/2022/08/image-495.png) Select the USB flash drive 5\. Click the Select button under the Boot selection. Locate the Ubuntu ISO file and click OK. ![Locate and select the Ubuntu ISO file](https://adamtheautomator.com/wp-content/uploads/2022/08/image-496.png) Locate and select the Ubuntu ISO file 6\. Click the Partition scheme selection box and choose the suitable partition scheme for your target system ([MBR or GPT](https://www.partitionwizard.com/partitionmagic/uefi-vs-bios.html)). Depending on your computer’s BIOS mode, select MBR for _Legacy_ and GPT for _UEFI_. This example will choose [GPT](https://adamtheautomator.com/mbr-or-gpt/) since the computer’s BIOS mode is _UEFI_. As you can see, the Target system value automatically changes when you change the Partition scheme. ![Select the partition scheme and target system](https://adamtheautomator.com/wp-content/uploads/2022/08/image-497.png) Select the partition scheme and target system Related:[MBR or GPT? Which Partition Style to Use?](https://adamtheautomator.com/mbr-or-gpt/) 7\. Leave all other settings to their default values, and click Start. ![Start flashing the USB drive](https://adamtheautomator.com/wp-content/uploads/2022/08/image-498.png) Start flashing the USB drive 8\. If you see the message, ISOHybrid image detected, select Write in ISO Image mode (recommended), as shown below, and click OK. ![Select Write in ISO Image mode](https://adamtheautomator.com/wp-content/uploads/2022/08/image-499.png) Select Write in ISO Image mode 9\. A warning pop-up shows, asking you to confirm that it is ok to destroy all data on the USB flash drive. Click OK to continue. ![Confirm erasing data](https://adamtheautomator.com/wp-content/uploads/2022/08/image-500.png) Confirm erasing data Rufus starts processing the bootable USB drive. Depending on your system and USB drive speed, this process could last several minutes. ![Rufus is processing the Ubuntu bootable USB drive](https://adamtheautomator.com/wp-content/uploads/2022/08/image-501.png) Rufus is processing the Ubuntu bootable USB drive 10\. Once Rufus finished writing to the bootable USB, the Status changes to Ready. Click CLOSE to exit Rufus. ![Exit Rufus](https://adamtheautomator.com/wp-content/uploads/2022/08/image-502.png) Exit Rufus ## Disabling Secure Boot Before you install Ubuntu on a partition alongside Windows 10, you must first disable the [Secure Boot](https://docs.microsoft.com/en-us/windows-hardware/design/device-experiences/oem-secure-boot) in your computer’s UEFI firmware settings. Why? When Secure Boot is on, you cannot install Linux or older versions of Windows. To disable secure boot, follow these steps. 1\. Open an elevated PowerShell window. Related:[Discover How to Run PowerShell as Administrator](https://adamtheautomator.com/powershell-run-as-administrator/) 2\. Run the below command. ```powershell shutdown.exe /r /o /f ``` 3\. The computer restarts and shows you the advanced boot menu. Click Troubleshoot. ![Click Troubleshoot](https://adamtheautomator.com/wp-content/uploads/2022/08/image-503.png) Click Troubleshoot 4\. Next, click Advanced options. ![Click Advanced Options](https://adamtheautomator.com/wp-content/uploads/2022/08/image-504.png) Click Advanced Options 5\. Under Advanced options, click UEFI Firmware Settings. ![Click UEFI Firmware Settings](https://adamtheautomator.com/wp-content/uploads/2022/08/image-505.png) Click UEFI Firmware Settings 6\. Once you’re in the BIOS interface, locate the Secure Boot setting and set it to disabled. This process is different between computer brands and models. The screenshot below [shows how to disable secure boot on a Lenovo ThinkPad X1 computer](https://download.lenovo.com/bsco/index.html). ![how to disable secure boot on a Lenovo ThinkPad X1 computer](https://adamtheautomator.com/wp-content/uploads/2022/08/image-506.png) [how to disable secure boot on a Lenovo ThinkPad X1 computer](https://download.lenovo.com/bsco/index.html) 7\. Once you’ve disabled secure boot, save the changes and exit the BIOS. At this point, the computer should reboot to Windows 10. ## Booting to USB and Install Ubuntu on a Partition Alongside Windows 10 You’ve disabled the secure boot and are ready to install Ubuntu on a partition alongside Windows 10. Ensure that the bootable USB drive you created is still attached to the computer and follow the below steps to boot to USB and install Ubuntu on a partition alongside Windows 10. 1\. Click Start → Power and SHIFT+CLICK on Restart. ![Shift+Click Restart](https://adamtheautomator.com/wp-content/uploads/2022/08/image-507.png) Shift+Click Restart 2\. On Choose an option page, click Use a device. ![Click Use a device](https://adamtheautomator.com/wp-content/uploads/2022/08/image-508.png) Click Use a device 3\. Next, click the USB device from the list. In this example, the bootable USB is the UEFI USB Device. ![Click the bootable USB device](https://adamtheautomator.com/wp-content/uploads/2022/08/image-509.png) Click the bootable USB device 4\. The computer reboots into the bootable USB device and shows you the GRUB bootloader, as shown below. Press Enter to boot to Ubuntu. ![Boot to Ubuntu](https://adamtheautomator.com/wp-content/uploads/2022/08/image-510.png) Boot to Ubuntu 5\. Next, click Install Ubuntu. Related:[How to Install Ubuntu 20.04 \[Step-by-Step\]](https://adamtheautomator.com/install-ubuntu/) ![Click Install Ubuntu](https://adamtheautomator.com/wp-content/uploads/2022/08/image-511.png) Click Install Ubuntu 6\. Select your keyboard layout and click Continue. ![Select the keyboard layout](https://adamtheautomator.com/wp-content/uploads/2022/08/image-512-1024x768.png) Select the keyboard layout 7\. Choose your installation options. This example leaves the default selections. Click Continue. ![Choose the installation options](https://adamtheautomator.com/wp-content/uploads/2022/08/image-513.png) Choose the installation options 8\. On the Installation type page, select Install Ubuntu alongside Windows Boot Manager and click Next. This option is what you must choose for dual-boot scenarios. ![Choose to install Ubuntu alongside Windows](https://adamtheautomator.com/wp-content/uploads/2022/08/image-514.png) Choose to install Ubuntu alongside Windows 9\. Next, select the drive where you’ll install Ubuntu on a partition alongside Windows 10. In this example, there is only one drive in the system. Click and drag the divider until the Ubuntu partition (on the right) space shows at least 20.0 GB, and click Install Now. ![Select the drive and allocate the partition size](https://adamtheautomator.com/wp-content/uploads/2022/08/image-515.png) Select the drive and allocate the partition size 10\. At the confirmation prompt that appears, click Continue. This step allows the installer to commit any previous partition changes. ![Allow previous partition changes](https://adamtheautomator.com/wp-content/uploads/2022/08/image-516.png) Allow previous partition changes 11\. Click Continue to confirm writing the new partition changes. The Ubuntu installer will create the new partition and format it using the ext4 filesystem. ![Confirm new partition changes](https://adamtheautomator.com/wp-content/uploads/2022/08/image-517.png) Confirm new partition changes 12\. Next, enter your name, computer name, username, and password, and click Continue. ![Enter your details](https://adamtheautomator.com/wp-content/uploads/2022/08/image-518.png) Enter your details At this point, the process will install Ubuntu on a partition alongside Windows 10, and you only need to wait for the setup to finish. ![Install Ubuntu on a partition alongside Windows 10](https://adamtheautomator.com/wp-content/uploads/2022/08/image-519.png) Install Ubuntu on a partition alongside Windows 10 13\. Click Restart Now after the installation. ![Click Restart Now](https://adamtheautomator.com/wp-content/uploads/2022/08/image-520.png) Click Restart Now ## Dual-Booting to Ubuntu and Windows After the restart, you will see the GRUB boot menu that lists **Ubuntu** and **Windows**. In this example, you’ll boot to Ubuntu first. 1\. Highlight Ubuntu from the list and press Enter. ![Boot Ubuntu](https://adamtheautomator.com/wp-content/uploads/2022/08/image-521.png) Boot Ubuntu Related:[Ubuntu GRUB Linux Bootloader and Configuration](https://adamtheautomator.com/ubuntu-grub/) 2\. Click your username, enter your password, and press Enter to log in. ![Log in to Ubuntu](https://adamtheautomator.com/wp-content/uploads/2022/08/image-522.png) Log in to Ubuntu 3\. After successfully signing in to Ubuntu, you must test whether your computer can still boot to Windows, your primary operating system. To do so, restart the computer. ![Restart the computer](https://adamtheautomator.com/wp-content/uploads/2022/08/image-523.png) Restart the computer 4\. On the GRUB menu, highlight the Windows Boot Manager and press Enter. ![Boot to Windows 10](https://adamtheautomator.com/wp-content/uploads/2022/08/image-524.png) Boot to Windows 10 5\. Log in to your Windows 10 account and confirm that Windows is still working. ![Login to Windows 10](https://adamtheautomator.com/wp-content/uploads/2022/08/image-525.png) Login to Windows 10 ## Troubleshooting a Missing “Install Ubuntu alongside Windows Boot Manager” Option Step 8 above assumes the Ubuntu installer detects your Windows installation. Sometimes it does not. Instead of the _Install Ubuntu alongside Windows Boot Manager_ option, you only see _Erase disk and install Ubuntu_ and _Something else_, and the partition list shows raw device names such as `sda` and `sda1` with no Windows label. Those device names are how Linux identifies storage. `sda` is the whole disk, and `sda1` is the first partition on it. A second disk appears as `sdb`, and an NVMe SSD normally appears as `nvme0n1` instead. If the list is short – a single `sda` with one partition – you are probably looking at the USB installer itself rather than your Windows disk. Stop and check before you write anything to it. Work through the causes below in order. Each one hides the alongside option for a different reason. ### You Created a Formatted Partition Instead of Free Space You do not need to create a separate _D:_ NTFS volume for Ubuntu. In the guided **Install Ubuntu alongside** workflow, the installer can resize an existing Windows partition and let you choose how much space Ubuntu should use. If you use **Manual partitioning**, shrink the Windows NTFS volume in Disk Management and leave the freed space **unallocated**. The Ubuntu installer can then create Linux partitions in that space. A formatted NTFS volume is not the same as unallocated space. If you already created a _D:_ volume and want to reclaim it for manual partitioning, copy its files elsewhere before you delete the volume. > _**Caution:** Deleting a volume erases everything stored on it. Copy any files off that drive letter before you delete it._ ### Fast Startup Left the Windows Partition Dirty Windows Fast Startup hibernates the kernel instead of shutting down completely. That leaves the NTFS filesystem in a dirty state, so the Ubuntu installer cannot mount it and cannot identify it as Windows. Open Control Panel → Power Options → _Choose what the power buttons do_, click _Change settings that are currently unavailable_, and clear the _Turn on fast startup (recommended)_ checkbox. Save the change, then run `chkdsk C: /f` from an elevated command prompt and reboot to clear any remaining dirty flag. ### The SATA Controller Runs in Intel RST or RAID Mode Some PCs use Intel Rapid Storage Technology (RST) or RAID instead of AHCI. Ubuntu can access some RST or RAID layouts but cannot access every configuration. Firmware names and controls vary by model and vendor, including Dell. Do not assume that every Dell computer requires a controller change. If the installer reports an RST conflict or cannot access the Windows disk, check the UEFI firmware for a SATA mode, VMD, or RST option. Review Ubuntu’s [Intel RST installation reference](https://ubuntu.com/desktop/docs/en/latest/reference/intel-rst-during-ubuntu-installation/) before you change the setting. > _**Warning:** An unprepared switch from RST or RAID to AHCI can prevent Windows from starting, commonly with `INACCESSIBLE_BOOT_DEVICE`. Back up your data first. Check BitLocker and Intel Optane before you change the firmware setting._ Ubuntu’s current procedure combines registry preparation and Safe boot in one sequence. They are not two alternative methods. Follow Ubuntu’s maintained [Reconfigure Windows to use AHCI](https://ubuntu.com/desktop/docs/en/latest/how-to/reconfigure-windows-to-use-ahci/) guide. It covers the registry changes, BitLocker and Optane checks, Safe boot, the firmware change, and final controller verification. ### The USB Booted in Legacy Mode but Windows Uses UEFI If the installer boots in Legacy/CSM mode, it cannot read the GPT partition table and EFI System Partition that a UEFI Windows install depends on. Confirm your firmware mode with `msinfo32` as described earlier in this tutorial, then make sure both halves match: choose _GPT_ in Rufus for a UEFI system and _MBR_ for a Legacy system. When you pick the boot device, select the entry prefixed with _UEFI:_ rather than the plain device name. ### Falling Back to Manual Partitioning If none of the above restores the alongside option, you can still install manually. Shrink the Windows volume from Disk Management first and leave the freed space unallocated. Then choose _Something else_ in the installer and create one `ext4` partition in that unallocated space with the mount point set to `/`. Allocate at least 30GB. > _**Caution:** The _Device for boot loader installation_ field decides whether Windows still boots. On a UEFI system, select the existing EFI System Partition – a small FAT32 partition of roughly 100MB to 500MB. On a Legacy system, select the whole disk, such as `/dev/sda`, and not a partition._ ## Conclusion That’s it! You’ve successfully configured your computer to dual-boot Windows and Ubuntu! In this article, you have learned how to install Ubuntu on a partition alongside Windows 10. You have also learned how to disable secure boot to install Ubuntu. Finally, you’ve installed Ubuntu on partition and logged in to your new system. You can now boot to Windows 10 and Ubuntu on demand and enjoy the best of both operating systems on one computer. 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