On June 1st 2015, qualifying Windows 7 and Windows 8.1 PCs and tablets will start seeing the Get Windows 10 icon in their taskbar notification area to be able to reserve your free upgrade to Windows 10 when released on July 29th 2015.
The KB3035583 Windows Update is responsible for adding Get Windows 10 to Windows 7 and Windows 8.1 PCs and tablets. Originally the KB3035583 update was optional to install. Microsoft has now changed KB3035583 to be recommended, which will have KB3035583 download and install automatically.
This tutorial will show you how to hide or remove the ‘Get Windows 10’ icon on the taskbar in Windows 7 and Windows 8.1 if you do not wish to reserve your free upgrade to Windows 10 when released.