A Windows Vista-based or Windows 7-based computer does not start because the master boot record (MBR) has been corrupted. When you try to use the Startup Repair tool to fix the MBR, the Startup Repair tool reports that no problem was found.
Note You can access the Startup Repair tool on the Windows Vista or Windows 7 installation disc that is appropriate for your version of Windows.
View the article in the Microsoft Knowledge Base:
You can use the Bootrec.exe tool in the Windows Recovery Environment (Windows RE) to troubleshoot and repair the following items in Windows Vista or Windows 7:
- A boot sector
- A Boot Configuration Data (BCD) store
To run the Bootrec.exe tool, you must start Windows RE. To do this, follow these steps:
- Put the Windows Vista or Windows 7 installation disc in the disc drive, and then start the computer.
- Press a key when you are prompted.
- Select a language, a time, a currency, a keyboard or an input method, and then clickNext.
- Click the operating system that you want to repair, and then click Next.
- In the System Recovery Options dialog box, click Command Prompt.
- Type , and then press ENTER.
Bootrec.exe optionsNote If rebuilding the BCD does not resolve the startup issue, you can export and delete the BCD, and then run this option again. By doing this, you make sure that the BCD is completely rebuilt. To do this, type the following commands at the Windows RE command prompt:
/FixMbrThe /FixMbr option writes a Windows 7 or Windows Vista-compatible MBR to the system partition. This option does not overwrite the existing partition table. Use this option when you must resolve MBR corruption issues, or when you have to remove non-standard code from the MBR.
/FixBootThe /FixBoot option writes a new boot sector to the system partition by using a boot sector that is compatible with Windows Vista or Windows 7. Use this option if one of the following conditions is true:
/ScanOsThe /ScanOs option scans all disks for installations that are compatible with Windows Vista or Windows 7. Additionally, this option displays the entries that are currently not in the BCD store. Use this option when there are Windows Vista or Windows 7 installations that the Boot Manager menu does not list.
/RebuildBcdThe /RebuildBcd option scans all disks for installations that are compatible with Windows Vista or Windows 7.
Additionally, this option lets you select the installations that you want to add to the BCD store. Use this option when you must completely rebuild the BCD.