How to Update Windows 10 on Low Storage Space


If you use Windows 10 on a laptop or tablet with low storage space, or you haven’t performed clean-ups on your internal storage drive in ages, you likely have run into problems when trying to download and install an OS update before.

However, insufficient storage space doesn’t mean you can’t update your operating system to the latest version. Many of you don’t know this, but it’s possible to install new Windows 10 builds on virtually any drive. All you need is two USB flash sticks.

Windows 10 already has a feature called “Reserved Storage,” which pre-allocates a small percentage of available storage space to ensure that critical update installations go smoothly. The problem is that it might not work as intended in your case, especially if your PC is severely constrained on disk space.

This guide will show you how you can update Windows 10 on PCs with low storage space in just a few simple steps.

Installing the latest Windows 10 build on low storage space

Updating to the newest version of Windows 10 on a desktop or laptop with insufficient disk space is pretty straightforward. All you have to is connect an external storage device with plenty of free space for bootable media. Here are the requirements:

  • Two USB flash drives (16 GB or higher)
  • Two free USB ports on your computer (You can use a USB hub)
  • A separate PC for creating an installation media

Creating a Windows 10 installation drive

You can use Microsoft’s Media Creation Tool to turn your USB stick into a Windows bootable media. Simply connect it to your second computer and perform the following steps:

  1. Launch your preferred web browser and visit the Windows 10 download site.
  2. Scroll down to the “Create Windows 10 installation media” section and click Download tool now.
  3. Go to your Downloads folder and double-click to launch the MediaCreationToolxxxx.exe file.
  4. On the “Windows 10 Setup” window, click Accept to agree to the terms and conditions.
  5. After that, select “Create installation media (USB flash drive, DVD, or ISO file) for another PC” and click Next.
  6. Uncheck the box next to the “Use the recommended options for this PC” option, choose the correct language, Windows 10 edition, and system architecture, then click Next to continue.
  7. Select the USB flash drive option when prompted to choose which media to use, and click Next.
  8. Now select the correct USB flash drive from the list of removable drives and hit Next.
  9. Finally, click Finish when you are ready to go.

Upon completing the steps, the Media Creation tool will begin downloading the necessary installation files and create a bootable partition on your external USB storage device. For those who are wondering, you will need it to update your primary Windows 10 PC on low storage space.

Updating to the latest Windows 10 version from USB flash drive

Now that you have your bootable Windows installation media, follow the below steps to update Windows 10 to the newest available version on your computer with low disk space.

  1. First, plug in your bootable USB flash drive to your PC, and then connect the other empty USB drive.
  2. Once your computer detects both external storage devices, open File Explorer from the desktop or Start menu.
  3. Head over to the This PC menu from the left sidebar, then visit your bootable USB flash drive’s root directory from the “Devices and drives” section.
  4. Double-click the setup.exe file to open the Windows 10 Setup window.
  5. When the setup window appears, click Next below the welcome screen, followed by accepting the terms and conditions.
  6. On the “Windows needs space to update” page, click the drop-down menu next to External Storage Device, choose your empty USB flash drive, and then click Next.
    Note: Windows 10 lets users use a secondary storage device for update installations, assuming it has enough free space.
  7. After that, click Open next to “Recycle Bin,” “Downloads,” and “Storage Use” options to free up some disk space on your computer.
    Note: Your PC’s primary storage volume must have some free space to continue with the update, even when you temporarily use an external drive for the installation.
  8. Once you manage to free up enough disk space, click Refresh to proceed.
  9. Make sure there’s a right tick next to “Keep personal files and apps” (otherwise, you will lose your data) and click Next.
  10. At last, hit the Install button and wait for the update process to take place.

When Windows 10 is done upgrading to the latest version, your computer will boot you straight to the login screen. Since this is simply an update, you won’t have to go through Windows’ first-time setup wizard (OOBE or Out-of-box experience) again.

Optional: Enable Compact OS on Windows 10

If your Windows 10 PC is still running low on storage space, consider enabling the “Compact OS” feature. What it does is store the Windows system files in compressed form, reducing the footprint of the operating system and freeing up plenty of disk space.

Though with Compact OS enabled, you might experience performance slowdowns on your device. It makes sense considering your PC has to decompress a file every time you load it up.

Here’s how you can reduce the size of your current Windows 10 setup:

  1. Right-click the Start button and select the Command Prompt (Admin) option.
  2. In the CMD window that appears, type the following command:
    compact.exe /compactOS:always
  3. Now press the Enter key on your keyboard and wait for Windows to enable Compact OS.

After performing the above steps, go to File Explorer > This PC to check how much disk space is freed. Depending on your setup, it usually reclaims somewhere between 2 GB to 7 GB of storage.

When you feel that your computer has enough disk space, you can go ahead and disable Compact OS on Windows by running the compact.exe /compactOS:never command in Command Prompt.