In this text we’ll present you ways to manually restore an by chance deleted Windows EFI boot partition on a UEFI pc. We’ll take a look at a simple means to manually recreate system EFI and MSR partitions in Windows, which is able to permit you to boot the OS after by chance formatting or deleting an EFI partition. The directions in this text are related for all variations of Windows, from Win 7 to Windows 10.
Suppose that the EFI boot partition in your UEFI (non-BIOS) pc was by chance deleted or formatted (for instance, if you tried ). As a outcome Windows 10/eight.1/ 7 doesn’t boot appropriately, cyclically prompting you to choose the boot system (
Reboot and choose correct boot system or insert boot media in chosen boot system and press a key). Let’s determine whether it is attainable to begin Windows correctly after deleting the EFI partition (with a Boot Manager and BCD configuration) with out reinstalling the OS.
Warning. This information implements working with disk partitions and isn’t beneficial for newcomers. If you interpret the instructions wrongly, you’ll be able to by chance delete all information in your exhausting disk. It can be strongly beneficial to backup necessary information on a separate media.
GPT Hard Disk Partition Structure in Windows
Consider how the default partition desk of a bootable exhausting drive with GUID partition desk (GPT) on the pc ought to appear to be. You ought to have at the least the next partitions:
- EFI System Partition (ESP – Extensible Firmware Interface) — 100 MB (partition kind — EFI);
- Microsoft Reserved partition — 128 MB (partition kind — MSR);
- Primary Windows partition (the partition containing Windows).
This is the minimal configuration. These partitions are created by the Windows Installer if you carry out a clear OS set up on an unformatted drive. Computer producers or customers can create their very own partitions containing, for instance, Windows Recovery Environment () in the winre.wim file, a partition with the system picture backup supplied by the OEM (permits to roll again to the unique state of the pc), consumer partitions, and so on.
The EFI partition with the FAT32 file system is a compulsory partition on GPT disks on UEFI computer systems and has the GUID
c12a7328-f81f-11d2-ba4b-00a0c93ec93b. The default measurement of the EFI partition is 100MB (on superior format disks with 4KB sectors the dimensions of the EFI partition is 260MB).
The MSR partition (Microsoft System Reserved) on the GPT disk is used to simplify partition administration and is used for service operations (for instance, when changing a disk from primary to dynamic). This is a backup partition with the GUID label
e3c9e316-0b5c-4db8-817d-f92df00215ae. The MSR partition doesn’t obtain a drive letter. This partition can’t retailer consumer information. In Windows 10, the dimensions of the MSR partition is simply 16 MB (in Windows eight.1 the dimensions of the MSR partition is 128 MB), the file system is NTFS. The MSR partition have to be positioned between the EFI partitions (ESP) and the first Windows working system partition.
The fundamental partition accommodates the put in Windows, applications and consumer information. Additional information partitions could also be current.
Missing EFI Partition in Windows
The EFI partition (related to the System Reserved partition on drives with the MBR partition desk), shops the boot configuration retailer (BCD) and plenty of information required to boot Windows. When the pc boots, the UEFI setting hundreds the bootloader (EFIMicrosoftBootbootmgfw.efi) from the EFI (ESP) partition and transfers management to it. The bootmgfw.efi executable launches the Windows Boot Manager, which hundreds configuration information from the BCD. Once the BCD is loaded, Windows begins booting by way of .
If the EFI partition is deleted or broken, you received’t find a way to boot Windows from that drive. UEFI error “
couldn't find efibootbootx64.efi – not discovered” seems , or an empty UEFI Shell prompting you to specify a boot system.
Also, you will be unable to boot Windows if the EFI partition is formatted with the NTFS file system. Even then performing a clear Windows set up, you’ll obtain an error:
Windows detected that the EFI system partition was formatted as NTFS. Format the EFI system partition as FAT32, and restart the set up.
How to Manually Create EFI and MSR Partitions on GPT Drive?
Since the system doesn’t boot appropriately, we’ll want Windows set up media with Windows 10 (Win eight or 7) picture or some other boot/rescue media. Boot from the set up media and on the primary set up display press the Shift+F10 key mixture. The command immediate window opens.
Run the disk and partition administration instrument:
List the exhausting disks linked to the pc (in our instance, there is just one disk, disk zero. The asterisk (*) in the GPT column implies that it makes use of the GUID partition desk).
*in the GPT column, then the disk partition desk is MBR. You want to just be sure you beforehand booted your pc in the native UEFI mode (in any other case, following this directions is pointless). If you’re positive that the partition desk kind has modified, it might be price .
Select this disk:
Display the record of partitions on the disk:
In our instance, solely two partitions are left on the drive:
- MSR partition — 128 MB;
- Windows system partition — 9 GB.
As you’ll be able to see, the EFI partition is lacking (it has been deleted).
Our job is to take away the remaining MSR partition in order that we now have at the least 228 MB of unallocated area on the drive (for MSR and EFI partitions). You can take away this partition utilizing the graphical Gparted or immediately from the command immediate (that’s precisely what we’ll do).
Important! Please, be extraordinarily attentive right here and don’t by chance delete Windows partition or partitions containing consumer information (if there are any).
Select the partition to take away:
And delete it:
Delete partition override
Make positive that there’s solely 9GB Windows partition left (in our case):
Now you’ll be able to re-create EFI and MSR partitions manually. To do it, run these instructions in diskpart context one after the other.
Select the disk:
Create a 100MB EFI partition, format it with FAT32 file system and assign a drive letter to it:
create partition efi measurement=100
Make positive that the 100 MB partition (an asterisk in entrance of the Partition 1) is chosen:
record partition choose partition 1 format fast fs=fats32 label="System" assign letter=G
Now you want to create an MSR partition with a measurement of 128 MB (in Windows 10, it’s sufficient to create 16 MB MSR partition).
create partition msr measurement=128 record partition record vol
In our case, the drive letter C: is already assigned to fundamental Windows partition. Otherwise, assign the drive letter to it as follows:
choose vol 1 assign letter=C exit
Repair the EFI bootloader and Windows BCD
After you may have created a minimal disk partition construction for the GPT drive on the UEFI pc, you’ll be able to proceed to copy the EFI boot information to the brand new partition and create a bootloader configuration file (BCD).
Copy the EFI setting boot information from the listing of your drive the place your Windows is put in:
mkdir G:EFIMicrosoftBoot xcopy /s C:WindowsBootEFI*.* G:EFIMicrosoftBoot
xcopy /s C:WindowsBootEFI*.* G:EFIMicrosoftBoot
Rebuild the Window BCD bootloader configuration:
g: cd EFIMicrosoftBoot bcdedit /createstore BCD bcdedit /retailer BCD /create /d “Windows Boot Manager” bcdedit /retailer BCD /create /d “My Windows 10” /software osloader
You can change the caption “My Windows 10” for some other.
The command returns the GUID of the created entry.Iin the following command put this GUID as a substitute of .
bcdedit /retailer BCD /set default bcdedit /retailer BCD /set path EFIMicrosoftBootbootmgfw.efi bcdedit /retailer BCD /set displayorder
The following bcdedit instructions are run in the context:
bcdedit /retailer BCD /set system partition=c: bcdedit /retailer BCD /set osdevice partition=c: bcdedit /retailer BCD /set path WindowsSystem32winload.efi bcdedit /retailer BCD /set systemroot Windows exit
Restart your pc… In our case it didn’t boot from the primary time. Try the next:
- Turn your PC off;
- Unplug (bodily)your exhausting drive;
- Turn your PC on, wait until the boot error window seems () and switch it off once more;
- Plug your drive again.
Then in our case (the check happened on the VMWare digital machine with UEFI firmware) we had to add a brand new merchandise to the boot menu by choosing the EFIMicrosoftBootbootmgrfw.efi file on the EFI partition.
In some UEFI menus, by analogy, you want to change the boot precedence of partitions.
After all these actions, your Windows ought to boot appropriately.
Tip. If one thing doesn’t work, it is strongly recommended to guarantee that solely EFI partition has the boot flag. You can do it utilizing GParted LiveCD.