Last year, Microsoft added a new feature to Windows 10 that encourages users to configure the system services 'powered by a Microsoft account' with a full-screen notification prompt when the system boots for the first time after an upgrade or fresh installation.
In general, this prompt should come only when the system boots after OS installation, but recently some customers (including me) have reported that they are getting this screen without updating the system.
If you are one of such users, and if you don't want Windows 10 to nag you once again with this full-screen notifications, here you have few steps to disable it.