Microsoft is going to auto-update Windows 10 v1803 and older to Windows 10 May 2019 Update (v1903)

Windows 10 April 2018 Update is nearing its end of support, Microsoft now wants its users to upgrade to the latest version of Windows 10 to provide continued support. Windows 10 users running older version of the operating system will be automatically updated.

Are you nearing to the end of Windows 10 support life-cycle? Check for updates to upgrade to the latest Windows 10 May 2019 Update (version 1903).

Starting 16th July 2019, Microsoft is initiating the installation of Windows 10 May 2019 Update to customers having Windows 10 version 1803 or older (Home or Pro). If you are one of them, you will start seeing the notification of Windows 10 May 2019 Update.

In a support document Microsoft stated:

We are initiating the Windows 10 May 2019 Update for customers with devices that are at or nearing end of service and have not yet updated their device. Keeping these devices both supported and receiving monthly updates is critical to device security and ecosystem health. Based on the large number of devices running the April 2018 Update, that will reach the end of 18 months of service on November 12, 2019, we are starting the update process now for Home and Pro editions to help ensure adequate time for a smooth update process.

If you don't want to get Windows 10 May 2019 Update (version 1903) at this moment, you will be able to pause the update for up to 35 days. Open the Windows 10 settings app (Win + I) and then navigate to the Update & Security | Windows Update page.

If you are looking for the Windows 10 May 2019 Update ISO/DVD image for offline or clean installation, here's a quick trick by which you can download it directly from the Microsoft site for free.