I have an Acer Aspire Z22-780 all-in-one desktop that was configured to boot into Windows 10 via EFI.
I have since upgraded the system to boot into Windows 11, similarly via EFI.
Recently however, I was informed that I did not have a proper boot device, and was unable to boot into Windows 10 or 11 via EFI. When I attempted to use the boot selection menu to select a USB Windows recovery/installer, I was immediately taken back to the boot selection menu. Similarly, selecting my SSD resulted in the same, while letting it try to find a boot device resulted in being told an improper boot device was selected.
If I disable Secure Boot and enable CSM/Legacy Boot, I am able to install Windows onto any SATA drive via MBR. However, when I reenable EFI and/or Secure Boot, I am unable to boot to any such device.
I suspected something happened to the BIOS, so I attempted to flash it from the non-EFI install of Windows, only to be given an error that an unsupported platform was detected. I obviously can't boot into a EFI flash drive to flash the BIOS, because again... it cannot detect any EFI device (except strangely, a Microsoft Surface SSD I previously intended to get data from that was connected to a USB adapter).
Does anyone know what may have happened, and how I can get my system to recognize EFI devices again?
(Thread was edited to add model name to the title)