Ok, this happened today, after a really strange BSOD with DPC_Watchdog_violation, strange because the pc is power on 24/7 100% stable, the bios on my mainboard (Biostar TZ68k+) started acting weird, that giving out CMOS failed, it hangs when i choose to
view boot priority and save settings, a clear cmos did not help, but everything returned to normal after re-flashing the bios.
But now the problem is, i cant boot Windows 8 anymore, as the mainboard is UEFI and the hard disk never had the boot sector or the bcd, it was on the bios as "Windows boot manager" as a boot unit, but now is dissapeared and i have no idea on now bring
it back, automatic repair with a repair pendrive fails, i tried the old method on placing the boot sector and bcd on the hard disk with
bootsect.exe /nt60 C: /force
bcdboot.exe C:\Windows /s C:
but it does not work either its just a back screen, that whould have worked with win7, but it does not here.
bootrec.exe /rebuildbcd and it says "the requested system device cannot be found"
Did you ever try to install any other unsigned operating system on your laptop? There are reports of laptops that have been bricked I hope that is not the problem. It might be the EFI partition that doesn't have the bootx64.efi file it must be corrupt.
This is a very serious issue as this is a new firmware a lot of people are still trying to understand if I were u I wont tamper with anything because if your laptop is not bricked yet and you keep tampering with it. You could brick it. For now I wont give
any advice but for you to take it back to the manufacturer or a technician that knows what he is doing. I cant fix it over the internet.
To me its a very serious issue because Windows 8 almost killed my motherboard, the bios was in a very bad state after the bsod.
It was a uneventfull day, no new programs, drivers or anthing in about 3 months, also i never have other os. And the computer has no stability problems and S.O. had all the updates installed.
It was just a bsod, and "Windows boot manager" dissapeared from the bios, also corrupting it, the bios hanged when tryied to view hard disks, boot prioritys and save bios, after re flashing, it returned to normal.
After the bios returned to normal i attempted to repair the Windows 8 install, using a repair pendrive generated from another pc with windows 8, but automatic repair failed.
I can not use the old MBR method because the partition is GPT, with BCD store being on the MST, but since the UEFI bios not longer has the opcion, i was unable to keep booting the Windows 8 install.
Also tryied the "refresh my pc" and "reset" options on the repair disk, but it did say that the device was locked, but i never wanted to do that, i just wanted to repair boot and BCD store, on the MBR was 2 commands, but no idea on how to do it with GPT