Windows won't boot in UEFI mode, deleted EFI partition.

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  1. Posts : 18
    Windows 10 Pro
       #1

    Windows won't boot in UEFI mode, deleted EFI partition.


    Okay, so the other week i received a new Clevo P650SE laptop. The laptop only had a 500GB 7200RPM HDD with Windows 10 to begin with, so yesterday i added my Samsung 840 EVO SSD. As i wanted this to now be the primary drive, i made another new installation of Windows onto here. After doing this, the system now displayed a boot selection at startup with the choice between the new Windows 10 installation on my SSD or the old one on the HDD.

    As i no longer wanted to use the HDD for running Windows, i decided it would be best to delete Windows from this drive. So i booted onto an Ubuntu USB and wiped the entire drive of it's data in GParted, which included three different partitions. This seemed perfectly fine to me at the time, because i had a the new installation from the SSD showing up in the boot manager.

    However, when i rebooted the machine and attempted to boot into the new installation on the SSD, it gives me this message:

    "The boot configuration data from your PC is missing or contains errors.
    File: /EFI/Microsoft/Boot/BC Error code: 0xc000000f"


    I have tried everything to recover the system but nothing has worked. Startup repair from my Windows USB doesn't do anything, the system reset wouldn't operate because it stated that the partition was locked.

    Nothing with the Command Prompt is helping me either, i have done 'bootrec /fixmbr', 'bootrec /fixboot' and 'bootrec /rebuildbcd', but the last command returns the following error:

    "The requested system drive cannot be found."


    I also did 'bcdboot C:/Windows' but that also refused to work. I assumed the reason for this might be because the drive didn't have a letter, but when i attempted to add a letter is says:

    "The specified drive letter is not free to be assigned."


    Both drives in my laptop have now been completely wiped and converted to MBR, but even with the two drives empty the original message still appears when booting my Windows USB in UEFI.

    I'm kind of scared because i have only had this laptop a couple of weeks and it's already completely messed up. I can boot the Windows USB in Legacy and install Windows as normal, but of course i'm looking to have it back on UEFI as it was before.

    Any help would be massively appreciated as i'm rather stressed about this at the moment.

    Last edited by OnePlus; 25 Aug 2015 at 12:30.
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  2. Posts : 187
    Windows 10 Pro
       #2

    You have to make a Windows USB that has UEFI support on it.

    You can best use RUFUS for this and use "partition scheme for UEFI".

    This should work.
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  3. Posts : 18
    Windows 10 Pro
    Thread Starter
       #3

    Rudy Mas said:
    You have to make a Windows USB that has UEFI support on it.

    You can best use RUFUS for this and use "partition scheme for UEFI".

    This should work.
    Yeah, i have already done that. Unfortunately the problem seems to be with the EFI partition on the original hard drive which i deleted by accident.
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  4. Posts : 187
    Windows 10 Pro
       #4

    Well, this worked for me.

    I had to make this kind of USB on my HP ProBook, else I couldn't set me BIOS to SecureBoot / UEFI Native (Without CSM).

    Normally, it doesn't matter what is on de harddrives, because it finds all the boot up information on the USB stick. The harddrives in the system doesn't even have to have a partition on it for this.

    How did you create the USB stick? The only program that worked for me was RUFUS. The tool to make bootable USB's from a downloaded Windows 10 from Microsoft didn't work for me
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  5. Posts : 107
    Windows 10
       #5

    OnePlus said:
    Both drives in my laptop have now been completely wiped and converted to MBR, but even with the two drives empty the original message still appears when booting my Windows USB in UEFI.
    Quote from this post: UEFI Boot Mode (installing using the GPT partition style) and Legacy BIOS Boot Mode (installing using the MBR partition style).

    1. How to create UEFI Boot Mode compatible Windows 8/10 64-bit USB flash drive, which is only bootable in UEFI Boot Mode.

    Format your USB flash drive. Note: You need to choose the FAT32 file system (see screenshot below).

    When formatting is complete.
    - In Windows 8/10, mount the Windows 8/10 64-bit ISO image file by right-clicking the ISO image file and choosing Mount. If you don’t see Mount command from the context menu, go to Open with -> Windows Explorer instead.
    - Select everything in the mounted ISO image file, and copy them into the USB flash drive you prepared earlier.

    Windows won't boot in UEFI mode, deleted EFI partition.-format-removable-disk.png
    UEFI Boot Mode do not use boot sectors on the hard drive (and the USB flash drive) and do not require active partition to be set.
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  6. Posts : 18
    Windows 10 Pro
    Thread Starter
       #6

    Rudy Mas said:
    Well, this worked for me.

    I had to make this kind of USB on my HP ProBook, else I couldn't set me BIOS to SecureBoot / UEFI Native (Without CSM).

    Normally, it doesn't matter what is on de harddrives, because it finds all the boot up information on the USB stick. The harddrives in the system doesn't even have to have a partition on it for this.

    How did you create the USB stick? The only program that worked for me was RUFUS. The tool to make bootable USB's from a downloaded Windows 10 from Microsoft didn't work for me

    I see what you mean, but i am confident there is nothing wrong with the USB because i have used it on this laptop previously with out issue. The bootable USB was created using Rufus, the same tool that you used. When i created the USB, i selected the option for a both UEFI and MBR compatibility. This is what i'm struggling to understand, i don't see why the drives should make any difference under these circumstances.
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  7. Posts : 187
    Windows 10 Pro
       #7

    OnePlus said:

    I see what you mean, but i am confident there is nothing wrong with the USB because i have used it on this laptop previously with out issue. The bootable USB was created using Rufus, the same tool that you used. When i created the USB, i selected the option for a both UEFI and MBR compatibility. This is what i'm struggling to understand, i don't see why the drives should make any difference under these circumstances.
    That doesn't work. You need to choose "GPT partition scheme for UEFI" and formatting in FAT32.

    The one you made, will only boot in Legacy mode.
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  8. Posts : 18
    Windows 10 Pro
    Thread Starter
       #8

    Rudy Mas said:
    That doesn't work. You need to choose "GPT partition scheme for UEFI" and formatting in FAT32.

    The one you made, will only boot in Legacy mode.
    In my original post i didn't state this because i wanted to keep things simple, but the laptop actually came with Windows 8 and i wiped the drive and upgraded straight to Windows 10 using this USB in UEFI mode. I can try using the other mode but i don't think it would make any difference.
      My Computer


  9. Posts : 187
    Windows 10 Pro
       #9

    It will, trust me.

    As I understood, your system came with Windows 10 installed, so it probably had an EFI partition on it. This was used by your USB stick when it booted. Now that it is gone, the USB stick can't find the information anymore it needs to boot. That's why you have to create the USB stick in a way that all the necessary information is on it, so it doesn't need anything from other sources.
      My Computer


  10. Posts : 18
    Windows 10 Pro
    Thread Starter
       #10

    Rudy Mas said:
    It will, trust me.

    As I understood, your system came with Windows 10 installed, so it probably had an EFI partition on it. This was used by your USB stick when it booted. Now that it is gone, the USB stick can't find the information anymore it needs to boot. That's why you have to create the USB stick in a way that all the necessary information in on it, so it doesn't need anything from other sources.
    Hmm, okay i do understand what you mean for sure now. You raise an interesting point and at the moment i am currently making the new USB with only the UEFI option enabled. I'm still a bit nervous about this though, because as i stated in the previous message the laptop actually came with Windows 8 installed and i wiped the hard drive and upgraded to Windows 10 afterwards. So at this point, i imagine the hard drive would possibly have been in the same condition as it is now, without the EFI partition, but i can't quite remember how i wiped it that time.

    I'll let you know what happens in a short while. :)
      My Computer


 

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