KB3035583
Get Windows 10
The Microsoft Get Windows 10 Update Notification Scam
An icon appears in the Windows icon tray with a nagging notification "Get Windows 10" which is actually part of an application that appeared in late April 2015 as a recommended Windows update (KB3035583). Microsoft abused their security update system to push an advertisement popup onto their customer computer systems.
KB3035583 loads an executable (GWX.exe) TSR that loads with Windows and uses system memory. It behaves like malware. KB3035583 is classified as a malware PUP.
You can remove KB3035583, however, it will likely install again if you use automatic updates from Microsoft. You need to uninstall the update, then go into Windows Update and hide the update from appearing on the list.