You don’t need a bootable USB flash drive or Media Creation Tool to install Windows 11 on a computer already running Windows 10. You can simply mount the ISO file to File Explorer and run the upgrade setup.

Although you would typically use the Media Creation Tool to perform an in-place upgrade or a bootable USB flash drive to do a clean installation, it’s also possible to use the Windows image mounting capability to load the ISO file to launch the Windows 11 setup and continue with the installation.

In this guide, you will learn the steps to perform an upgrade or clean installation of Windows 11 without a bootable USB or Media Creation Tool.

How to install Windows 11 from ISO without USB

To install Windows 11 without a USB flash drive, use these steps:

  • Download Windows 11 ISO file.
  • Right-click the ISO file, select the Open with submenu, and choose the Windows Explorer option.
  • Click on the mounted drive from the left navigation pane.
  • Double-click the Setup file to begin the Windows 11 upgrade process.
  • (Optional) Click the Change how Windows Setup downloads updates option.
  • Select the Not right now option.
  • Click the Next button.
  • Click the Accept button to agree to the terms.
  • Click the Install button to upgrade while keeping your files and apps.

If you want to perform a clean installation of Windows 11, click the Change what to keep option, select the Nothing option, click the Next button, and then click the Install button.

Download Windows 11 ISO file.

Right-click the ISO file, select the Open with submenu, and choose the Windows Explorer option.

Click on the mounted drive from the left navigation pane.

Double-click the Setup file to begin the Windows 11 upgrade process.

(Optional) Click the Change how Windows Setup downloads updates option.

Select the Not right now option.

Click the Next button.

Click the Accept button to agree to the terms.

Click the Install button to upgrade while keeping your files and apps.

After you complete the steps, the upgrade process will begin and the computer will restart several times. After the installation, you may need to go through the out-of-box experience (OOBE) to finish configuring Windows 11.