> For the complete documentation index, see [llms.txt](https://desync-4.gitbook.io/desync-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://desync-4.gitbook.io/desync-docs/russkii/english/troubleshooting-and-support/windows-will-not-start-efi-boot-recovery.md).

# Windows will not start: EFI boot recovery

For Windows 10/11 installed in **UEFI/GPT mode**. This procedure restores EFI boot files when their corruption prevents Windows from starting.

**Do not format or delete PC partitions, and do not reset BIOS.** Enter commands one at a time and press Enter after each. If an error occurs or the result is unclear, stop and send a photo to [@desync\_support\_bot](https://t.me/desync_support_bot).

The photo shows an example error before Windows starts. Choose the appropriate route in step 1.

![](https://content.gitbook.com/content/2IqdwbRpQj7CdFx59AIG/blobs/z3Zyv1u2DhF8d52RWAFD/spaces%2FnitGYSBvlczRLpWdhsJO%2Fuploads%2FsK99nRqj82vFQKLun8zT%2FDESYNC_EFI_bootloader_error.png?alt=media\&token=1d9cd95c%20dfdd%204822%208879%20c077699e98d2)

## 1. Open the recovery Command Prompt

* **Automatic Repair is already shown:** Advanced options → Troubleshoot → Advanced options → Command Prompt.
* **Windows begins loading but will not start:** interrupt startup twice by holding the power button after the Windows logo appears. On the third startup, allow recovery to open and follow the route above. Do not keep repeating forced shutdowns.
* **Only BIOS or an error before Windows loading appears:** choose Windows Boot Manager in the boot menu. If Windows starts, stop; the commands below are unnecessary. If neither Windows nor recovery is available, use Windows installation USB media.

If BitLocker asks for a key, you need the PC owner's recovery key. [Microsoft recovery-environment guide](https://support.microsoft.com/en-us/windows/experience/backup-recovery/windows-recovery-environment).

Create installation media on another PC using [Microsoft's Media Creation Tool](https://support.microsoft.com/en-us/windows/deployment/install-upgrade/create-installation-media-for-windows). Use a USB drive of at least 8 GB; creating it erases the USB drive. Connect it to the affected PC, open Boot Menu (often F11, F12 or Esc, depending on the model) and select UEFI: your USB name. At the installer window, press Shift + F10. **Do not start installation. These commands cannot be entered in BIOS itself.**

## 2. Find the Windows volume

Enter:

```
diskpart
list volume
exit
```

Photograph the table. **W and S must be unused drive letters.** If either is occupied, contact support.

Check the letters in the table one by one, excluding X, which belongs to the recovery environment. For example:

```
dir C:\Windows\System32
dir D:\Windows\System32
dir E:\Windows\System32
```

If the path is not found, check the next letter. Find the volume that lists System32 files and folders, then find its volume number in the table.

**Stop and contact support if Windows is not found, appears on multiple volumes, the disk is locked or access is denied.**

## 3. Assign W to Windows and identify its disk

Replace N with the Windows volume number you found. Do not type the letter N or use a number from someone else's example.

```
diskpart
select volume N
detail volume
```

Record the physical Disk number shown. If multiple disks appear or the result is unclear, stop. Then enter:

```
assign letter=W
```

Wait for successful assignment. Stay in DiskPart.

## 4. Find the system EFI partition

Enter:

```
list disk
```

The recorded disk must have an asterisk **\*** in the GPT column. Without it, this guide does not apply; stop.

Replace K with the disk number:

```
select disk K
list partition
```

Find the single partition of type **System**. Do not select Primary, Reserved or Recovery.

Replace M with the system partition number:

```
select partition M
detail partition
```

The lower table must show **FAT32**. If no system partition exists, there are several or the filesystem differs, stop and send a photo to support. [Microsoft's EFI partition guidance](https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/configure-uefigpt-based-hard-drive-partitions?view=windows-11).

## 5. Assign S to EFI and restore files

```
assign letter=S
```

After successful assignment:

```
exit
dir W:\Windows\System32
```

If the System32 files and folders are listed again, run:

```
bcdboot W:\Windows /s S: /f UEFI
```

Wait for **Boot files successfully created**. If an error occurs, stop and photograph both the command and its result.

## 6. Test startup

Close Command Prompt, shut down the PC and remove the installation USB if used. Turn the PC on; if needed, select Windows Boot Manager for your system disk.

If Windows starts, recovery is complete.

If Windows Boot Manager is missing or the error persists, contact support. Using /s S: restores the files but does not create a Windows Boot Manager entry in UEFI memory; additional boot configuration may be needed. [Microsoft BCDBoot reference](https://learn.microsoft.com/en-us/windows-hardware/manufacture/desktop/bcdboot-command-line-options-techref-di?view=windows-11).

## What to send support

Complete the questionnaire in [@desync\_support\_bot](https://t.me/desync_support_bot). State the step where you stopped and attach photos of the error, list volume, list partition and the last command's result, if you reached those steps. Agree on further actions in the ticket.