I believe you may be having a hardware or BIOS issue.
My desktop was taking approximately 5 minutes to display after power on or restart. After a restart I used Ctrl, Alt, Del to get to task manager, services, and disabled AppReadiness and the desktop displayed.
No desktop problem when I started in safe mode:
Temporary fixes:
1 restoring drive image from prior to update
2 in-place install of windows using media creation tool
3 recovery using earlier restore point. Even when the recovery failed sometimes the problem went away for a few days.