 FYI: Here is how I fixed this 1. Boot in Safe Mode 2. Run Dism /online /cleanup-image /scanhealth (and also checkhealth though the DISM step wasn't actually necessary since no issues found) 3. sfc /scannow (this is actually the step that fixed the issue, got a message that issues were found and fixed... not quite sure how the corruption happened while updating in the first place... but that's what fixed my problem. Hopefully I won't see this ever again...   
Has anyone else experienced this? Since installing updates last week my Alienware R10 hangs after I enter the windows 10 pro pin. After entering the pin I get the spinning wheel for a lot longer than usual, then a black screen with the cursor for perhaps 2-3 minutes before windows explorer finally load. I haven't installed any new software in a while, other than the updates. I believe there was the most recent Bios, the GPU driver, the Wifi/Bluetooth drivers and a few Windows 10 updates. I've tried a couple of trouble shooting steps I found online for that issue but so far no luck. Any ideas? As far as I can tell everything works fine once the windows menu and desktop finally appear... but not cool to have to wait 3 minutes each time I reboot the PC. Hitting Alt+Ctrl+del does work while the screen is black.
Aurora R10, black screen with cursor after entering PIN since last updates