In the past the GWX (Get Windows Ten) update could be stoped close by clicking the red “X” windows close button in top right corner.  GWX is used to control update to WIN10 for WIN7 and WIN8 home users. Habitually knowing it’s been safe in past to prevent WIN10 installation, many users won’t even read the changed message. 

The new GWX requires user to click a link to either delay or cancel the GWX update. The previous behavior required you to click on something to INSTALL.  The changed behavior is that you now must click on something to PREVENT THE INSTALL.  Compounding this further are folks who have clicked thru the red “X” without reading the changed GWX and then they might let their PCs idle for a few days (past the install opt out target date) …. When they wiggle the mouse again they are in the WIN 10 EULA “accept” or “decline” prompt.

Users who carefully read the WGX will have no issues, with the new approach

http://www.computerworld.com/article/3070460/windows-pcs/microsoft-makes-final-aggressive-windows-10-upgrade-push.html

http://www.computerworld.com/article/3044518/microsoft-windows/users-seethe-as-windows-10-arrives-while-their-backs-are-turned.html

“If you click on OK or on the red ‘X’, you’re all set for the upgrade and there is nothing further to do,” the document stated. The “X” Microsoft mentioned is one way to close a window in Windows.  But Microsoft’s interpretation of clicking the X is contrary to decades of practice in windowed user interfaces (UIs) and normal user expectations: To users, shutting a window by clicking the X tells the OS to remove the notification or application frame without expressing an opinion, selecting an option or calling up an operation.  Instead, Microsoft equates closing the window with approving the scheduled upgrade.