On the morning of Nov. 13, I opened my 2014 HP Envy TouchSmart 17" notebook to find it locked in a Windows Automatic Repair loop. I ran boot diagnostics and received short DST failure code QC601S-785A9W-MFGH7F-60VE03. This was a first-time lockout occurrence, and I think that Microsoft updated my Windows 10 the previous night (I can't get into the Windows GUI to find out). I learned from this Website that a short DST failure could be caused by many things, so I did some further diagnosis on my HDD. I ran chkdsk /f /r on C: drive, and found no significant problems. Windows fixed minor issues, then I ran diskpart sel disk 0, list partition and list volume, and learned that my C: drive is a GPT drive, and all volume partitions are healthy. I also noticed that my HP Envy HDD is happily communicating with the network backup drive (WD MyBook Live), even though I cannot access the Windows GUI. Since the HP Recovery utility was unable to help with repairs, I downloaded "Windows 10 bootable Media Creation Tool for another computer" to a USB drive on this notebook, and booted up the HP Envy with it (the Envy would not boot to the internal HP Recovery Tool). My plan was to get into a recovery mode Windows 10 GUI so I could access some Windows 10 configuration tools, but when I found a Startup Repair option in the Media Creation Tool recovery selections, I decided to try it again. I started that repair about 13-1/2 hours ago, and it still seems to be running. Right now, I'm looking at a black screen with an arrow cursor that I can move with my mouse, and a normal rotating "working" circle attached to it that randomly blinks on and off fairly rapidly during rotation, while the upper edge of my normally-hidden task bar blinks on and off in a separate random sequence at the bottom of my screen (the whole taskbar is not visible). I have the following four questions:
1. How long should I let Startup Repair run before I give up on it and take my chances with a Windows 10 clean install?
2. If I shut down Startup Repair before it is finished, would I risk data corruption?
3. If I stop Startup Repair, how should I do it with the least risk to my system?
4. After Startup Repair is finished (one way or the other), I will first try to reboot normally. If that still doesn't work, any recommendations for next steps? I'm a little leery about trying a Windows 10 clean install from the USB drive before I have GUI access to the installed Windows 10.