SF315-52-52YN with 1TB HDD and 16GB Optane got the "No Bootable Drive" issue for no apparent reason. BIOS was only able to see the Optane, could not see the HDD. Was somehow able to get into Windows Recovery Mode, but this was not helpful because opening Command Prompt, issuing the command "diskpart" and then "list drive" showed no drives. Opened the laptop, pulled the HDD and installed it in my PC, where it worked fine and no bad sectors were found, so it's not a dead HDD.
The real problem was that an automatic Windows update, possibly interacting with the Optane stick, got stuck into a Pending Install state, preventing the laptop's firmware from seeing the HDD anymore.
1. Go to BIOS, under MAIN change SATA Mode from "RST with Optane" to AHCI, under Security set Supervisor Password to something easy like "test", under Boot set Secure Boot from Enabled to Disabled. One or more of these may require a reboot in between, or you may have to do them in a different order. The BIOS should now be able to see the HDD and you should now be able to actually use Windows Recovery to do something.
2. In Windows Recovery, go to Command Prompt, run:
dism /image:c:\ /get-packages
When you get a list of packages, scroll up, look for packages that say "Install Pending". Highlight the package name with the mouse, press "Enter" to copy.
Then run this for each of the packages that say "Install Pending"
dism /image:c:\ /remove-package /packagename:RIGHT CLICK THE MOUSE TO PASTE IN THE PACKAGE NAME
exit, reboot
3. For me, at this point Windows still wouldn't reboot. I used the Windows Recovery to Uninstall Updates, but upon doing so got an error 0x800F082F and CBS.log told me "Cannot finalize session because an exclusive session is pending". There is an article that tells you how to get around that:
But I needed to figure out how to run Command Prompt as an administrator in order to edit the Registry while in WIndows Recovery. You do that by using this command in Command Prompt:
net user administrator /active:yes
4. After this, Windows booted! Went to Windows Update, had it start installing updates, but it was unable to install the April 14 2020 Windows 10 Cumulative Update KB4549951 no matter what I did, and it won't let any other updates come in without finishing that, so the Windows install still seems broken. The 1TB HDD also seems pretty slow now, so I ended up taking out both the 1TB HDD and the Optane 16GB stick and installing a 512GB NVME M.2 drive where the Optane stick was and installing a fresh Windows 10 on it. I'm working on figuring out if I can run a second drive in the 2.5" SATA slot while booting from the M.2 slot.
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