I have a Windows 7 computer upgraded to windows 8.1 and all was working well until I installed update KB2919355.  I can put my computer to sleep, but when I click the space bar the power light briefly turns from orange to the familiar blue and then shuts down completely.  I restored to an earlier date and confirmed I could successfully wake it from sleep.  I then installed only the aforementioned update and the problem resurfaced.  I hope I am not the only one and a fix will be available.  Meanwhile I am trying my best to insure this update does not get installed.

Thank you.