Microsoft issued a large Windows update days after the WannaCry malware pandemic infected thousands of computers and led to a huge wave of Windows users updating their OSs to close the SMBv1 exploit left open by Windows until March when a leak of NSA intel made the vulnerability, as well as the NSAs exploit tool, public.
The update was unusually large, taking over an hour on some computers.
Most noticeable changes after the update: Microsoft adds a mail icon to the toolbar (currently, more people use Google for mail); OneDrive is added to the tools menu; Windows Defender Security Center also added to toolbar. In "Apps & Features," Microsoft OneConnect (paid Wi-Fi cellular) is added." Techies have recommended the removal of OneConnect, which has been part of Windows "Pre-Installed Apps" for a while.
It also "installs" apps that you already have installed, so it is more difficult to find what things Microsoft actually added when you update. However, Windows installed a lot of new apps (their own) in this update.
Microsoft removed the option to set the program to open types of files with. Now, it only opens automatically with Windows new file viewing apps. (This can be corrected by going to "Default Apps" in Start Menu and selecting apps for media types.)