I get 0xc000000f when booting. How to fix the boot system manually?

Environment:
-UEFI system. On diskpart.com I found 'Try turn off EFI boot mode in BIOS'. I see no option in my UEFI setup utility to turn off (U)EFI.
-Win7 64-bit on a SSD. On the C-drive.
-DVD player.
-The 'EUFI setup utility' sees - if I NOT use 'Windows Boot Manager' - the SSD as AHCI. And it sees the single DVD player both as AHCI AND UEFI boot option.
-I do NOT want to reinstall. I want to be able to boot in the current Windows (with about 150 programs installed, and 15.000 preferences set in Windows and in the programs). So I guess I need to repair the Windows boot files.
-I have a Win8.1 CD. With this I can go to CMD. That's all I can do; no other repair options work or are accessible. If I try 'Renew PC', it says the drive is in use. If I try 'Startup repair', it says the PC can't be repaired with Startup repair. Logfile: [nill]. If I try to use Restore point, it says I have to select which Restore point, but it does not list any or give any option to select one. It then says 'Reboot ans select ...'. Which, obviously, doesn't work - as then I get the 0xc000000f error again.
-I have a Vista64-bit CD. Booting from this I can do only two things: CMD, or repair boot: with this it says it found Windows7 and offers to add a Windows7 entry in the boot options. But that fails. Maybe some boot file is read only.
-I have several Windows7 CD's, but not a usable one: System Recovery Options says: 'This version of System Recovery Options is not compatible with the version of Windows you are trying to repair'. I also tried some ISO's, making the USB-stick bootable with Windows7-USB-DVD-Download-Tool.exe. Those give the exact same 'not compatible' error.
-I still see all the files on the C-drive in CMD (booting from the Win8 or WinVista CD).
-The Vista diskpart gives an error; returning nothing.
-'List disk' in the the Win8 diskpart says:
Disk 0: Online; Size: 232 GB; Free: 1024 KB; GPT: *
Disk 1: No Media; Size: 0 B; Free: 0B; GPT: [no *]
-But 'dir' gives: 2 GB free (I also can copy files larger than 1024 KB; so it seems diskpart is wrong here about the 'Free' info).

Symptons:
-I had the problem that no image appeared at all whatsoever (also no beeps or different LED's from the mainboard), when turning on the PC. I currently use another videocard; now there's image again.
-After inserting the other video card, I get the 0xc000000f error, and 'The boot selection failed because a required device is inaccessible': https://www.minitool.com/images/uplo...n-failed-1.png

Questions:
-Where are the boot files, and how are they named?
-Does the SSD use hidden partitions (required for booting Windows)?
-How would I try to manually add that Windows7 (C:\Windows) boot entry which Vista tried, but failed?
-Is it because it is GPT (not MBR), the command 'Bootrec /RebuildBcd' does not work? It says:
Total indentified Windows installations: 1
[1] C:\Windows
'Add installation to boot list? Yes/No {Yes results in: see next line}
The Requested System Device Cannot Be Found.

iko22 said:

Hello blueyellow,

Can you set AHCI in BIOS? It is normal for AHCI to be set On these days, but your OS may have be installed with AHCI On or Off. It is important for the BIOS AHCI to match the OS installation, for the Boot Manager to boot correctly from Disk.

I see no general/overall option to make 'everything' AHCI. I think the mainboard is about 7 years old.

The SSD is already set as/to AHCI. If I manually select boot options in the 'UEFI setup utility', I see:
# Windows Boot Manager [Which was and is the default first boot option.]
# AHCI P0: Samsung SSD
# AHCI P5: CDDVDW 224
# UEFI: CDDVDW 224DB

...while I only have 1 DVD-player in the machine. But it sees two different boot options for the that DVD-player; AHCI (name '224') and UEFI ('224DB'). But why isn't there an UEFI option for the SSD? (Not that I know if that would help...)

I just tried (in CMD via boot from the Win8 CD):
• bcdedit /export C:\BCD_Backup
It gives error:
The store export operation has failed.
The Requested System Device Cannot Be Found.

If I rename c:\boot\bcd to c:\boot\bcd_old, there is no change. Still 0xc000000f.

To use the automated system recovery options - you need to use boot media that matches the os.

You also need to boot the repair media in the correct mode.

Try booting the windows 7 media using the ahci selection.

You can borrow my windows 7 boot media which has explorer included so you can see what you are doing

17514x64v15.iso

The iso can be burned to cd/dvd though it is better to extract it to usb stick using usb7ice or similar

Usb7ice.zip

Have a look and see if the ssd is gpt partitioned.

If you are using efi, there should be an esp partition, which is where the boot critical files are kept.

when you know the drive letters the recovery media has assigned to the esp partition and the windows partition , you can use nt6repair (it is on the desktop). Also tick the box which says "tick for efi"

SIW2 said:

Have a look and see if the ssd is gpt partitioned.

If you are using efi, the(re should be an esp partition, which is where the boot critical files are kept.

when you know the drive letters the recovery media has assigned to the esp partition and the windows partition , you can use nt6repair (it is on the desktop). Also tick the box which says "tick for efi"

Diskpart
# list disk
Shows: Disk 0: Online 232GB Free: 1024KB GPT: *
So, yes. I see I already posted that in my first post .

(I think MBR is ancient? Well... Windows7 is getting old, too... :P Still, on many things, I prefer Win7 over Win10... and WinXP over Win7; g.e. the option to have a column which shows the size of a folder, is a major problem in the newer Windows versions.)

Before using nt6repair, I ran diskpart (via your ISO via 'AHCI: SanDisk'):
# select disk 0
# list partition
Shows: 4 partitions:
Partition 1: System 100MB
Partition 2: Reserved 128MB
Partition 3: Primary 45GB [This is C]
Partition 4: Primary 187GB [This is D]
So, there are two partitions without drive letter.

# detail disk
Shows: 3 volumes: C, D, and a hidden volume of 100MB.

BTW: I can't use a mouse whilst in your ISO; I guess it hasn't loaded USB-drivers (it also doesn't see the USB-stick; only in CMD). Luckily, the PC has an PS2 keyboard connection, so I can use a keyboard running the ISO.