Ever since this update [2017-10 Cumulative Update for Windows 10 Version 1703 for x64-based Systems (KB4041676] my SP4 keeps hanging or the screen freezes. I have to use reset to get the system going again. I have noticed that Cortana often (but not always) shows a mad flicker when this happens, although I have turned off every function of Cortana I can locate and removed it from the taskbar. Any suggestions gratefully received. I use my SP4 in court, and the problem seems to occur every time I have to speak from my notes on my tablet!