Notebook Boot and Lockup

After Windows 10 KB4025342 & KB4025376 updates I get a black screen with movable cursor for 4.1 minutes after log in screen then the full display returns. BIOS and all drivers are up to date.

Windows 10 10.0.15063 HOME edition

Intel i7-5500U @2.4 GHz

Graphics Intel HD graphics 5500

Grapics driver: 20.19.15.4549 11/10/2016

System SKU: L0Q51UAR#ABA

BIOS: AMI F.46  6/1/2017

8G RAM

Screen set for PC screen only, max resoultion

I have tried setting and unsetting fast startup but to no avail. I have removed AVAST third party antivirus and CC cleaner temporarily to reduce any start up conflicts, Malware bytes however is still on the machine.  I can enter Safe mode from the black screen and I have run all Windows and HP diagnostics and updates but that has not helped.

During the black screen task manager shows some minimal CPU and memory activity but certainly nothing unusual.

Guessing this is a graphics driver/second display issue but the driver is from late in 2016.  There is a newer Intel 5500 graphics generic driver but it is not validated for this machine. I have not tried to force an update to the generic graphics driver.  I have also tried connecting an external display through HDMI but it has the same black screen issue as the PC display.

I can roll back to before the newest Windows updates but that of course is not a permanent solution. I'm guessing I'm not the only person having issues with this update.