How to clean install Windows 10 21H1, May 2021 Update

Windows 10 21H1, May 2021 Update, is available starting May 18 for compatible devices, and to avoid possible problems, the best way to upgrade is to perform a clean installation using a USB flash drive bootable media.

Usually, the recommended method is to perform an in-place upgrade using Windows Update, but changing the current setup can lead to errors and many other problems due to compatibility issues and custom configurations. A clean install of Windows 10 21H1 minimizes the risks of issues because it deletes everything on the hard drive and sets up a fresh copy of the operating system.

If you have had the same installation for a long time, starting from scratch with a fresh copy of the operating system can improve performance, booting times, memory usage, and resolve existing problems. However, if you are upgrading to the new version, there is an exception. On devices running version 20H2 or 2004, it is not necessary to go through the reinstallation process. Since Windows 10 21H1 is a small update based on version 2004, devices running one of the two most recent releases only need the enablement package to upgrade, which installs quickly like a cumulative update using Windows Update.

You should only use the Media Creation Tool to upgrade from an older version (for example, November 2019 Update) or fix problems with the current setup.

In this hands-on video, you will learn the steps to properly perform a clean installation of the Windows 10 May 2021 Update on a computer using a USB bootable media created with the Microsoft Media Creation Tool.

Clean install Windows 10 21H1 from USB

Before diving into the process, you first need to create a USB flash drive with the Media Creation Tool, then start the computer with the bootable media to access the Windows Setup wizard. Also, you have to make sure the device can boot from USB, which means that you may need to adjust the BIOS or UEFI settings. However, since the settings are different on most devices, you have to check your manufacturer support website for more specific details.

To perform a clean installation of Windows 10 21H1 (May 2021 Update), use these steps:

Start your PC with the Windows 10 21H1 USB install media.
Press any key to continue.
Click the Next button.
Click the Install now button.
Click the I don’t have a product key option if you are doing a reinstallation. If Windows 10 was already activated, after the installation, reactivation will happen automatically.
Select the edition of “Windows 10” that your license key activates (if applicable).
Check the I accept the license terms option.
Click the Next button.
Select the Custom: Install Windows only (advanced) option to clean install Windows 10 21H1.
Select each partition in the hard drive you want to install Windows 10 and click the Delete button. (Usually, the “Drive 0” is the drive that contains all the installation files.)

Warning: When you delete a partition, it also deletes all data on the drive. Also, it is not required to delete the partitions from a secondary hard drive.
Select the hard drive (Drive 0 Unallocated Space) to install Windows 10 21H1.
Click the Next button.
After the installation, on the first page of the out-of-the-box experience (OOBE), select your region setting.
Click the Yes button.
Select your keyboard layout setting.
Click the Yes button.
Click the Skip button if you do not need to configure a second layout.
If the computer is using an Ethernet connection, it will connect to the network automatically. If you have a wireless connection, you will need to set up the connection manually.
Select the Set up for personal use option if you are setting Windows 10 Pro. The Home edition does not have this option.
Click the Next button.
Confirm your Microsoft account email, phone number, or Skype identification to create an account.
Click the Next button.
Confirm your Microsoft account password.
Click the Next button.
Click the Create a PIN button.
Create a new PIN password.
Click the OK button.
Confirm your privacy settings that best suits your needs by turning on or off the toggle switch for each setting.
Click the Accept button.
(Optional) On the “Customize your device” page, select one or more ways you plan to use the device to allow the setup to suggest tools and services customization during this experience.
Click the Accept button to continue. Or click the Skip button to skip this part of the setup.
Click the Do it later button to skip linking your phone to your PC. (You can always do this from the Settings app.)
Click the Next button to allow OneDrive to backup your Desktop, Pictures, and Documents folders to the cloud automatically. Or click the “Only save file to this PC” option to skip this step.
Click the No, thanks button to skip the Office 365 setup.
Click the Accept button to enable Cortana. (If you want to use the “Hey Cortana” feature, also check the Respond when I say “Hey Cortana” option.)

Once you complete the steps, a clean install of Windows 10 21H1 will be performed on the computer.

For additional assistant, check this guide that includes every step to prepare, create a backup, and start with a new installation of Windows 10. If you want to speed up the installation process, you can also do an in-place upgrade using these instructions.