Chosen Solution
I currently have an Acer Swift 3 SF315-52 Laptop. I restarted the computer to fix an application bug, but when I tried to boot it up, it gave me a “No Bootable Device” Error. I looked into possible fix’s on the internet and most of them recommend changing the Boot Mode from UEFI to Legacy. However, this option is grayed out for me and I cannot change it. I have attempted to change many other settings in the bios to change the boot mode, but I have still not figured it out. Does anybody know how to fix this?
I would try booting from a flash drive with Windows on it and possibly run a disk check. Sounds like your boot disk may be either corrupted or the Windows installation got corrupted data and that requires a complete wipe of the drive through a disk partitioning app and a clean install of Windows. Hope this helps!