If it was purely Microsoft Windows update there would be 100,000s more people effective and they wouldn't be a small minority. Most all Windows 8.1 users have installed this update and are having no problem, that is why Microsoft is not going to provided any security or other updates if this update is not installed starting with the Monthly updates today. Hope this helps and if you need further assistance post and we will be glad to Help you.
The above opinion is mine and mine alone and doesn't necessarily reflect that of Microsoft, it's employees, or any other member of this forum.
"When we try to pick out anything by itself, we find it hitched to everything else in the Universe." -John Muir