MBR修復ツール：Windows 11/10でMBRを修復する4つの方法
アン MBR repair tool can rebuild damaged boot code and help fix errors such as “Operating System not found,” missing partitions, or Windows failing to start. In Windows 11 and Windows 10, you can first try the built-in Startup Repair or Bootrec commands. If the partition table is damaged, a tool such as TestDisk may be more suitable.
Before repairing the MBR, do not initialize or format a RAW or unallocated drive. If important files or partitions have disappeared, consider performing 失われたパーティションのデータ復元 before making write-based changes to the disk.
目次
Quick Comparison of MBR Repair Tools
The right MBR repair tool depends on whether the problem affects the Windows boot code, the Boot Configuration Data, or the partition table.
| 工具 | 最適 | 無料 | 主な制約 |
|---|---|---|---|
| Windows Startup Repair | Automatically fixing common Windows startup errors | はい | Cannot recover a severely damaged partition table |
| Bootrec.exe | Repairing MBR boot code, boot sectors, and BCD | はい | Requires access to Windows Recovery Environment |
| テストディスク | Finding lost partitions and rebuilding supported boot sectors | はい | Text-based interface may be difficult for beginners |
| GUI partition tool | Rebuilding MBR through a visual interface | 限定 | Some repair functions may require payment |
| Magic Data Recovery | Recovering files when a drive remains RAW or inaccessible | Free scan | Recovers data but does not directly rebuild the MBR |
注： Magic Data Recovery is a data recovery program rather than an MBR rebuilding utility. Use it when important files remain inaccessible before or after repairing the disk structure.
How Does an MBR Repair Tool Work?
The Master Boot Record is located in the first sector of an MBR-formatted disk. It contains bootloader code and a partition table describing the location and size of the disk’s partitions.
Malware, interrupted cloning, incorrect partition operations, unexpected shutdowns, and disk errors can damage this information. Depending on the type of corruption, an MBR repair tool may:
- Write new MBR boot code.
- Repair or restore partition table entries.
- Rebuild a damaged partition boot sector.
- Reconstruct Windows Boot Configuration Data.
- Restore a previously saved copy of the MBR.
However, an MBR repair does not fix every RAW, unallocated, or undetected drive. File system corruption, missing partition entries, bad sectors, and hardware failure require different solutions.
Also note that most Windows 11 computers use GPT and UEFI instead of the traditional MBR and Legacy BIOS configuration. Confirm the disk’s partition style before applying an MBR-specific repair.
When Should You Use an MBR Repair Tool?
Consider using an MBR repair tool when an MBR-formatted disk has one or more of the following symptoms:
- Windows displays “Operating System not found” or “Missing operating system.”
- Windows fails to boot after disk cloning or partition resizing.
- The system cannot find a bootable Windows installation.
- A partition disappears after the MBR or partition table is damaged.
- The disk appears unallocated because its partition entries are missing.
- The bootloader was damaged by malware, an interrupted update, or an unexpected shutdown.
An MBR repair tool is unlikely to help if the drive is not detected in BIOS/UEFI, makes unusual noises, disconnects repeatedly, or has serious physical damage.
4 Ways to Repair MBR in Windows 11/10
Method 1: Run Windows Startup Repair
Startup Repair is the easiest option when Windows cannot boot. It can automatically diagnose and repair certain startup problems, including damaged system files, corrupted BCD information, and some MBR-related errors.
- Enter the Windows Recovery Environment.
- 選択 トラブルシューティング.
- 選ぶ 高度なオプション.
- クリック スタートアップ修理.
- Select your Windows account if prompted.
- Wait while Windows checks and repairs the startup configuration.
Restart the computer after the process finishes. If Windows still cannot start, continue with the Bootrec method below.
Method 2: Repair MBR with Bootrec Commands
Bootrec.exe is a Windows command-line utility available in the Windows Recovery Environment. It can write new MBR boot code, repair the partition boot sector, scan for Windows installations, and rebuild BCD.
オープン トラブルシューティング > 詳細オプション > コマンドプロンプト, and then run the following commands one at a time:
bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcdThese commands perform different operations:
bootrec /fixmbrwrites new MBR boot code without overwriting the existing partition table.ブートレコード /fixbootwrites a new boot sector to the system partition.bootrec /scanossearches for Windows installations not currently listed in BCD.ブートレコード /rebuildbcdrebuilds the Windows Boot Configuration Data.When the commands finish, close Command Prompt and restart the computer. If
ブートレコード /fixbootreturns “Access is denied,” the EFI or system partition may require additional repair.
Method 3: Repair a Damaged Partition Table with TestDisk
Bootrec can repair Windows boot code, but it cannot reliably restore missing partition table entries. If the disk appears unallocated or a partition has disappeared, TestDisk may be more appropriate.
- Download TestDisk from the official CGSecurity website.
- Run TestDisk as an administrator.
- 選択 作成 to create a log file.
- Select the affected physical disk.
- Choose the detected partition table type, usually Intel/PC for an MBR disk.
- 選択 分析, 、その後に クイック検索.
- Review the partitions found by TestDisk.
- 用途 ディープ・サーチ if the expected partition is missing.
- 選ぶ 書く only when the displayed partition layout is correct.
Writing an incorrect partition structure can make data recovery more difficult. If you are unsure whether the detected partitions are correct, copy or recover important files before applying the changes.
Method 4: Use a GUI MBR Repair Tool
A graphical MBR repair tool may be easier for users who are uncomfortable with Command Prompt or TestDisk. Although the interface differs between products, the typical workflow is:
- Install the tool on a working computer.
- Create a WinPE bootable USB drive.
- Boot the affected computer from the USB drive.
- Select the correct physical disk.
- 選ぶ Rebuild MBR or a similar option.
- Select the MBR type that matches the installed Windows version.
- Apply the change and restart the computer.
Carefully verify the selected disk before applying the repair. Rebuilding the MBR on the wrong disk or choosing an incompatible boot type can prevent the system from starting.
When an MBR Repair Tool Will Not Solve the Problem
An MBR repair tool only addresses boot code or partition structure problems. It may not solve the issue in the following situations:
- The disk uses GPT and UEFI: Modern Windows 11 systems usually use GPT rather than the traditional MBR boot method.
- The disk is missing from BIOS/UEFI: This usually indicates a connection, controller, firmware, or hardware problem.
- The drive remains RAW: The NTFS or FAT file system may be damaged even if the MBR is valid.
- The disk has bad sectors: Repeated repair attempts may make the drive less stable.
- The partition table is missing: Bootrec can write new boot code, but it cannot automatically reconstruct lost partition boundaries.
- ドライブに物理的な損傷がある： Clicking sounds, repeated disconnections, or extremely slow reading require professional handling.
Do not initialize, format, or create a new partition on a drive that still contains needed data.
まとめ
ベスト MBR repair tool depends on the cause of the problem. Windows Startup Repair is suitable for automatic startup troubleshooting, while Bootrec can repair MBR boot code and rebuild BCD. If partitions have disappeared or the partition table is damaged, TestDisk or a dedicated partition tool may be required.
MBR repair does not automatically recover missing files or fix every RAW drive. If important data remains inaccessible, stop writing to the affected disk. Magic Data Recovery can scan RAW, inaccessible, and damaged partitions for recoverable files before you initialize, format, or rebuild the disk structure.
For additional help with missing or damaged partitions, see our lost partition data recovery guide.
Windows 7/8/10/11およびWindows Serverをサポート
MBR修復ツールに関するFAQ
Does MBR Repair Erase Data on the Hard Drive?
MBRとGPTの違いは何ですか？また、MBR修復ツールはディスクフォーマットを変換できますか？
Windowsの内蔵ツールでMBRエラーを確実に修正できますか？
MBRを修復してもドライブがRAWまたは未割り当てと表示されるのはなぜですか?
MBRの破損によってBIOSがドライブを認識できなくなることはありますか?
MBR修復中に間違ったディスクセクタが上書きされた場合はどうなりますか？
