Saturday, March 05, 2011
How To: Repair And Restore Windows 7 Master Boot Record (MBR)
How To: Repair And Restore Windows 7 Master Boot Record (MBR)
The Master Boot Record (MBR) will be created when you create the first partition on the hard disk. It is very important data structure on the hard disk drive. The Master Boot Record contains the Partition Table for the hard disk and a small amount of executable code for the Windows Vista boot start. The location of Master Boot Record files is always the first sector on the hard disk.When you start your Windows Vista computer, the BIOS (basic input/output system) looks for the MBR on the first sector of your hard drive. The MBR tells the BIOS which partition on the hard drive contains the operating system.When we try to boot after hardware testing procedures, we see just blank screen without any messages. It means the piece of code at the beginning of the MBR could not be executed properly. That’s why even error messages could not be displayed.Also when we try to boot into Windows Vista, we see an error message like “Operating System not found” and this error occurs with a broken Master Boot Record (MBR).
To Restore corrupted Windows Vista Master Boot Record(MBR),follow the simple procedures.
You can use the Bootrec.exetool in the Windows Recovery Environment (Windows RE) to troubleshoot and repair the following items in Windows Vista:
A master boot record (MBR)
A boot sector
A Boot Configuration Data (BCD) store
Note When you are troubleshooting startup issues by using the Windows RE, you should first try the Startup Repair option in the System Recovery Options dialog box. If the Startup Repair option does not resolve the issue, or if you must troubleshoot more steps manually, use the Bootrec.exe tool.
To run the Bootrec.exe tool, you must start Windows RE. To do this, follow these steps:
Put your Windows Vista 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 click Next.
Click Repair your computer.
Click the operating system that you want to repair, and then click Next.
In the System Recovery Options dialog box, click Command Prompt.
Type “Bootrec.exe”, (without the quotes) and then press ENTER.
Note: To start the computer from your Windows Vista installation DVD, your computer must be configured from BIOS to start from the DVD drive
Bootrec.exe options
The Bootrec.exe tool supports the following options. Use the option that is appropriate for your situation.
/FixMbr
The /FixMbr option writes a 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.
/FixBoot
The /FixBoot option writes a new boot sector to the system partition by using a boot sector that is compatible with Windows Vista. Use this option if one of the following conditions is true.
The boot sector has been replaced with a non-standard Windows Vista boot sector.
The boot sector is damaged.
An earlier Windows operating system has been installed after Windows Vista was installed. In this scenario, the computer starts by using Windows NT Loader (NTLDR) instead of Windows Boot Manager (Bootmgr.exe).
/ScanOs
The /ScanOs option scans all disks for installations that are compatible with Windows Vista. Additionally, this option displays the entries that are currently not in the BCD store. Use this option when there are Windows Vista installations that the Boot Manager menu does not list.
/RebuildBcd
The /RebuildBcd option scans all disks for installations that are compatible with Windows Vista. 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.
Note: 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:
bcdedit /export C:\BCD_Backup
c:
cd boot
attrib bcd -s -h -r
ren c:\boot\bcd bcd.old
bootrec /RebuildBcd
Note: If you are running a RAID array, if this does not help and you are recieving errors. Check in your BIOS and make sure the BIOS did not convert back to IDE.Windows Vista needs to see the compleate MBR, In a RAID setup the MBR is split between two drives.
How to Open the Local Group Policy Editor in Windows 7
This will show you how to open the Local Group Policy Editor in Windows 7.
Note
The Local Group Policy Editor is a Microsoft Management Console (MMC) snap-in that provides a single user interface through which all the Computer Configuration and User Configuration settings of Local Group Policy objects can be managed for your computer.
Computer Configuration
Administrators can use Computer Configuration to set policies that are applied to computer, regardless of who logs on to the computers. Computer Configuration typically contains sub-items for software settings, Windows settings, and administrative templates.
User Configuration
Administrators can use User Configuration to set policies that apply to users, regardless of which computer they log on to. User Configuration typically contains sub-items for software settings, Windows settings, and administrative templates.
Warning
You will need to be an administrator to open the Local Group Policy Editor.
The Local Group Policy Editor will only be available in the Windows 7 Professional, Ultimate, and Enterpise editions. You will not have the Local Group Policy Editor available in the Windows 7 Starter, Home Basic, and Home Premium editions.
Here's How:
1. Open the Start menu, and type gpedit.msc in the search line and press Enter. (See screenshot below)
NOTE: This file is located at C:\Windows\System32\gpedit.msc.
2. If prompted by UAC, click on Yes.
3. You can now set and manage the Local Group Policies on your computer to how you want them.
NOTE: For more details and information about how to use the Local Group Policy Editor, click on the blue ? toolbar icon.
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