As scary as this message is, it is recoverable and your programs and data are not lost.
Full Text Error Message:
Your PC/Device needs to be repaired. The Boot Configuration Data file is missing some required information. This article describes how to recover.
Error Code: 0xc000000d
Error Code: 0x00000034
You will need to use recovery tools. If you don't have installation media (like a disk or USB device), contact your PC administrator or PC/Device manufacturer.
When: On a reboot, typically on a Windows 10 (Windows 8) computer, laptop or desktop.
Do these steps to confirm the BIOS is set properly for boot. You will likely need to do these steps if you were trying to change the Boot Device order or if you had enabled the Legacy Boot options.
These steps vary by hardware vendor, but in general:
a) Cold-boot the machine, and open the BIOS Setup screen. Typically press F2 when the machine's brand-logo appears, just before Windows loads. If the BIOS setup key does not display, search the web for your particular computer. Some, for example, require pressing fn-F2. There is also a way to make a Windows setting change to force this condition on next reboot; details not here.
b) In the BIOS setup screen, confirm Boot Mode is set to UEFI. Confirm Secure Boot is ON.
Solution 1: USB Recovery Drive
If you had previously built a Windows 10 Recovery Drive,
a) Boot from this disk * Boot instructions, below
b) Select Repair.
The recovery drive is typically an 8GB USB -- and it has to be created from this same computer prior to this error. This cannot be built from another machine.
The trouble is, nobody has ever built this disk and even if you did, you likely can't find it. I clipped mine to the back of the computer.
For this article, you are too late, but the disk can be built with these steps:
a) From the desktop's search, type "Create a Recovery drive".
b) Follow the on-screen instructions and expect an hour to build. It will require an 8GB or larger USB thumb dive.
Solution 2: Windows 10 Installation Media
From any other computer, build a Windows 10 installation disk and use it to recover from this error.
a) Search Microsoft.com for "Windows 10 Media Creation Tool" or this link:
b) Download, saving the executable to your downloads directory.
c) Double-click to run the Media Creation Tool program stub (.exe).
d) When prompted, insert a blank DVD and allow it to build the disk. Optionally use a USB.
e) This will take 20 to 40 minutes to write. Label the disk as "Windows 10 Installation Media".
f) Insert the DVD/USB and reboot the computer, booting from the DVD or USB *
*Boot instructions, below
Getting to the boot menu varies by manufacturer.
For Dell, press F12 "Boot Options" at the hardware/BIOS banner
Boot to the DVD/USB disk from the BIOS screens:
1. At the Windows initial setup screen, click Next
2. In the lower right corner, select "Repair your computer" by typing "R"
3. Choose "Troubleshoot"
4. Select "Advanced options"
5. In Advanced, select "Command Prompt"
At the DOS Prompt, type this command:
Boot /fixmbr Press Enter
Bootrec /rebuildbcd (Selecting "A" - All when prompted)
type "Exit" to close the Command Prompt window.
7. From the Windows Setup screens, click "Continue"
The PC should now boot properly.
Consider building a Recovery Drive from the first solution, above.
Booting from a DVD or USB Drive
UEFI-protected disks are new to Windows 8 and Windows 10 and are designed to prevent programs from modifying the boot sectors - and they also block booting from an untrusted, unsigned USB or DVD.
Booting using a Microsoft program (such as the Windows Recovery Drive or the Windows 10 Media disk), or from a trusted disk imaging or virus vendor's disk will succeed. But the biggest problem is getting the PC to recognize it is allowed to boot from those devices.
See this Keyliner article: Setting Boot Order for DVD or USB (article pending)
Keyliner: Installing a Crucial SSD Drive