BOOTREC - CMD

Overview

The BOOTREC command is a Windows Recovery Environment (WinRE) tool that helps users recover from boot errors that may occur due to corrupted Boot Configuration Data (BCD) or missing system files. It is primarily used to fix boot issues and restore the master boot record (MBR) and boot sector. This command is essential for system administrators and users facing boot-related problems.

Syntax

To use BOOTREC, you need to boot from the Windows installation media or a recovery disk and open Command Prompt from the repair options. The basic syntax is:

BOOTREC /option

Where /option is replaced by specific flags that define the repair operation.

Options/Flags

/FixMbr – Writes a Windows 7/8/10-compatible MBR to the system partition. This does not overwrite existing partition tables. Use this option when there is MBR corruption or non-standard code.
/FixBoot – Writes a new boot sector to the system partition. This command is useful when a boot sector is replaced or corrupted, especially after installing another OS.
/ScanOs – Scans all disks for installations compatible with Windows and displays the entries currently not in the BCD store. Helpful for finding hidden installations.
/RebuildBcd – Scans all disks for installations suitable with Windows and allows you to select which to add to the BCD store. Use when starting Windows is problematic due to BCD corruption.

Examples

Repairing the Master Boot Record (MBR):
```
BOOTREC /FixMbr
```
This command is used when you suspect that malware or a custom script has corrupted the MBR.
Writing a New Boot Sector:
```
BOOTREC /FixBoot
```
Use this if your boot sector has been replaced by another operating system or damaged by malicious software.
Scanning for Windows Installations Not in BCD:
```
BOOTREC /ScanOs
```
Finds Windows installations not listed in the Boot Configuration Data.
Rebuilding the BCD Store:
```
BOOTREC /RebuildBcd
```
Useful for completely rebuilding the BCD if it gets damaged or corrupted.

Common Issues

Boot file not found: This usually occurs if the BCD is damaged. Using /RebuildBcd can help resolve this issue.
Permission errors: Running BOOTREC requires administrative privileges. Ensure you run the command prompt as an administrator.
Unsupported file systems: BOOTREC only supports file systems used by Windows (e.g., NTFS, FAT32).

Integration

Combine BOOTREC with other commands to automate recovery tasks. For instance, running CHKDSK before BOOTREC ensures the integrity of the file system:

CHKDSK C: /F /R
BOOTREC /FixMbr
BOOTREC /RebuildBcd

CHKDSK – Checks the filesystem and fixes issues on the disk.
DISKPART – A command-line utility for disk partitioning.
BCDBOOT – Used to copy critical boot files to the system partition and create a new system BCD store.

For official documentation and further reading, visit the Microsoft support page related to boot issues or the command-specific documentation provided with your version of Windows.