When a build of Windows 10 reaches its expiry date, certain events will occur on your computer. It is therefore imperative to know the expiration date of your Windows 10 Preview date and what will happen after the Windows 10 build reaches its expiration.
What happens when Windows 10 expires
If you see the Windows 10 Build expiration dates, you will notice that the build typically expires after 5 or 6 months.
1] Roughly 2 weeks before you Windows 10 build expires, you will start seeing warnings like – This build of Windows will expire soon. Once you start seeing this warning, you should take it seriously and backup all your data and check your Windows Update to see if any new build or upgrades are available. Alternatively, you can download the latest ISO file from Microsoft, mount it and launch setup.exe to upgrade to a newer build.
2] Once your build reaches the license expiration date, your computer will automatically reboot approximately every 3 hours. As a result of this, any unsaved data or files you may be working on, will be lost.
3] The computer will no longer boot, 2 weeks after the license has expired. After the expiration date is crossed, when you start your computer, you will see a Recovery message – Your PC/Device needs to be repaired message. You will not be able to log in to your computer. In this case, you will have to download the ISO file from another computer and then transfer the ISO file to some installation media. Once you have done this, you will have to boot the computer from the installation media to install the latest build of Windows 10
I would like say that it is therefore a good idea to have your Windows 10 always up-to-date and install all updates automatically. In fact this is probably also one of the reasons why in Windows 10 Update settings, Home users are give only one option and that is to install Windows Update automatically!