This article describes an error on devices with small free storage space upgrading to Windows 10, how to use an external storage device to perform the upgrade, and how to remove temporary files after an upgrade.
Computers that have smaller hard drives (32GB or less) or very full hard drives may encounter an error during upgrade to Windows 10. The Windows 10 upgrade wizard requires a large block of storage to create a backup of the previous operating system and to install Windows 10.
Use one of the following methods to complete your upgrade to Windows 10:
Freeing up space on the primary hard drive is the easiest way to create room to install the Windows 10 upgrade. Consider the following options:
If you cannot free up enough space on the primary drive to upgrade to Windows 10, you can attach a USB key (16GB or greater) or an external USB hard drive to the computer to finish the upgrade. Once you have attached a USB storage device, when the "Windows needs more space" screen appears, select the drive letter for the USB key or USB hard drive to continue with the installation.
After a successful upgrade to Windows 10, Windows preserves the option to remove Windows 10 and go back to your previous version of Windows. These files are automatically deleted a month after you upgrade. You may easily remove the temporary files used during the upgrade process to free up disk space. To delete these files now, follow these steps: