FIXMBR » mbr http://fixmbr.net FIXMBR is a computer repair training site for my students. Fri, 27 Aug 2010 18:04:57 +0000 http://wordpress.org/?v=2.9.2 en hourly 1 FIXMBR Vista http://fixmbr.net/fixmbr-vista/fixmbr-vista/ http://fixmbr.net/fixmbr-vista/fixmbr-vista/#comments Wed, 18 Nov 2009 20:36:53 +0000 gfrench http://fixmbr.net/?p=66 FIXMBR Vista

Bootrec

Use the Bootrec.exe (FIXMBR Vista or Windows 7) tool in the Windows Recovery Environment (Windows RE) to troubleshoot and repair the master boot record (MBR), boot sector, and the Boot Configuration Data (BCD) store.  Windows RE can also be used to troubleshoot startup issues.  There are two options, Startup Repair and System Recovery Options.  [...]]]> FIXMBR Vista

Bootrec

Use the Bootrec.exe (FIXMBR Vista or Windows 7) tool in the Windows Recovery Environment (Windows RE) to troubleshootfixmbr vista and repair the master boot record (MBR), boot sector, and the Boot Configuration Data (BCD) store.  Windows RE can also be used to troubleshoot startup issues.  There are two options, Startup Repair and System Recovery Options.  Bootrec.exe can be used to troubleshoot additional problems manually.

To run Bootrec.exe utility, you need to start Windows RE.  First startup the computer with the Windows install disk.  You might need to set the BIOS to boot first from the DVD/CDROM.  Select Repair Your Computer and then select the operating system you want to repair.   In the System Recovery Options box select Command Prompt and type bootrec.exe and press enter.   You can rebuild the BCD by typing bootrec /rebuildbcd to correct startup issues.  To correct a corrupted or infected MBR type bootrec.exe /FIXMBR to write a new MBR.  Bootrec /fixboot will write a new boot sector to the system partition to correct a damaged boot sector or non-standard boot sector for FIXMBR Vista.  If a Windows XP was installed after Vista or 7 you can use this command to restore the Windows Boot Manager by replacing Windows NT Loader (NTLDR).

Master Boot Record (MBR)

MBR is a 512 byte file located in the first sector on the hard drive.  It contains partition information and boot code for starting the operating system.

Recovery Console

Recovery console is a utility that can be started from the Windows install CD.  You can also install recover console.  Once installed you can select it when you first startup you computer.  It will be an option on a menu that is presented during the computer startup.

FIXMBR

The FIXMBR is a command used with Recovery Console with Windows XP that writes a new MBR to the first sector of a hard drive.  This command is used to fix or correct a corrupted or infected MBR.

The FIXMBR website has some additional articles you might find useful.

]]> http://fixmbr.net/fixmbr-vista/fixmbr-vista/feed/ 0 Fixboot http://fixmbr.net/fixboot/fixboot/ http://fixmbr.net/fixboot/fixboot/#comments Wed, 18 Nov 2009 19:49:29 +0000 gfrench http://fixmbr.net/?p=62 The Fixboot is a Recovery Console command that writes a partition boot sector to a system partition that you can specify.

Boot Sectors

Boot sector is a sector on a hard drive or data storage device that contains code for booting a program stored on some other part of the storage media.  The computer BIOS can be [...]]]> The Fixboot is a Recovery Console command that writes a partition boot sector to a system partition that you can specify.

Boot Sectors

Boot sector is a sector on a hard drive or data storage device that contains code for booting a program stored on some other part of the storage media.  The computer BIOS can be set to select any of several boot devices and then copies the first sector from the boot device to address location 0×7C00.

Different kinds of boot sectors can be encountered on computer hard disks and other storage devices.  A master boot record (MBR) is the first sector of a data storage device that has been partitioned. The MBR sector contains code to locate the active partition and start its Volume Boot Record.

Volume Boot Record (VBR)

A volume boot record is the first sector of a data storage device that has not been partitioned.  It contains code to load and start an operating system installed on that device or within that partition.

Valid boot sectors have a two-byte hex word 0xAA55, called the boot sector signature and must exist at the end of the sector.  If the signature is not present either the BIOS or MBR code will report an error message and halt any OS startup process.

The computer BIOS does not distinguish between VBR and MBR. The firmware will only load and runs the first sector of the storage device. floppy devices or USB flash drives will use a VBR to boot. Hard drives use an MBR. The MBR has the partitioning information and will start the VBR which will load the operating system.

Boot Sector Viruses

Since the code in the boot sector is first executed automatically the boot sectors have been targets for computer viruses. As a warning computer BIOS now have included a feature to prevent writing over the boot sectors without user permission.

FIXMBR

FIXMBR is a Recovery Console command that writes a new MBR to the first sector of a hard drive.  This command can be used to correct a corrupted or infected MBR.  The fixboot command write the partition boot sector.

The FIXMBR website has some additional articles you might find useful.

]]> http://fixmbr.net/fixboot/fixboot/feed/ 0 Fdisk MBR http://fixmbr.net/fdisk-mbr/fdisk-mbr/ http://fixmbr.net/fdisk-mbr/fdisk-mbr/#comments Wed, 28 Oct 2009 23:35:23 +0000 gfrench http://fixmbr.net/?p=38 The Fdisk MBR switch is an undocumented switch that can be used with DOS fdisk to replace or repair the MBR file.  This can be done if the MBR file becomes corrupted or infected.  WARNING if you have a multi-boot drive you could end up loosing access to one or all of your operating systems.  [...]]]> The Fdisk MBR switch is an undocumented switch that can be used with DOS fdisk to replace or repair the MBR file.  This can be done if the MBR file becomes corrupted or infected.  WARNING if you have a multi-boot drive you could end up loosing access to one or all of your operating systems.  It would be a good idea to backup the MBR or drive before you run Fdisk /MBR.  I use to have a lab where the computer and students all got infected with the NYB virus which attaches itself to the MBR files and then infects any drive that reads or writes files from the hard drive.  To correct the problem and get rid of the virus we would boot the computers from a clean DOS floppy or CD and run fdisk /mbr and this would correct the problem.  Once the student floppies or flash drives got infected the virus would migrate rapidly throughout the lab.  I wasn’t until we put on a good anti-virus program that we were able to clean and rid ourselves of the problem.  The fdisk mbr switch has helped in the past but good anti-virus software is a better long term fix.

FIXMBR

The FIXMBR website has some additional articles you might find useful.

]]> http://fixmbr.net/fdisk-mbr/fdisk-mbr/feed/ 0 MBR File http://fixmbr.net/mbr-file/mbr-file/ http://fixmbr.net/mbr-file/mbr-file/#comments Sat, 17 Oct 2009 19:52:18 +0000 gfrench http://fixmbr.net/?p=32 The MBR (master boot record) file is on the first sector, 512 bytes, of your hard drive.  This file contains the hard drive partition table, boot start-up program, and a drive signature.  The file resides outside the hard drive partitions on the first sector of the drive and can be repaired using fdisk mbr in [...]]]> The MBR (master boot record) file is on the first sector, 512 bytes, of your hard drive.  This file contains the hard drive partition table, boot start-up program, and a drive signature.  The file resides outside the hard drive partitions on the first sector of the drive and can be repaired using fdisk mbr in DOS or fixmbr command using the Windows recovery console.  It would be a good idea to backup the MBR before any changes or modifications are made.  There are many MBR utilities that can be found at CNET download for backing up, editing, or making changes to the MBR.  The boot start-up or sometimes referred to as the bootstrap program is used to start the operating system, which is a small machine code program that BIOS uses to start-up the operating system.  The last part of the MBR files is a 32 bit drive signature that uniquely identifies the hard drive.  Since the MBR file is the first file read before the operating system is loaded it has become the target of a number of viruses.  Once the MBR file is infected the viruses will copy themselves into memory and control the operating system.  Viruses will normally disable in virus protection and infect any files copies to another other device.

To better understand how the Fdisk program operates or the Recovery Console you can find those posts here at this site under the Categories.

FIXMBR

The FIXMBR website has some additional articles you might find useful.

]]> http://fixmbr.net/mbr-file/mbr-file/feed/ 0 FIXMBR http://fixmbr.net/fixmbr/fixmbr/ http://fixmbr.net/fixmbr/fixmbr/#comments Sat, 10 Oct 2009 02:41:57 +0000 gfrench http://fixmbr.net/?p=13 The FIXMBR is one of several Windows Recovery Console commands.  After you select the operating system and logon you can type FIXMBR at the prompt and the MBR (master boot record) is rebuilt and replaced with a new MBR file.  This can usually correct some of the startup problems with a corrupted or infected MBR [...]]]> The FIXMBR is one of several Windows Recovery Console commands.  After you select the operating system and logonfixmbr you can type FIXMBR at the prompt and the MBR (master boot record) is rebuilt and replaced with a new MBR file.  This can usually correct some of the startup problems with a corrupted or infected MBR record.  Since the MBR record is the first 512 bytes read on the boot hard drive it is also a target for many viruses.  If the MBR gets infected the virus can move into memory and control all other boot processes and disable any anti-virus programs.  Most anti-virus programs like AVG will detect and stop viruses, but if you boot the computer to an infect device, such as, a floppy or CD, it can infect the MBR.  Just rebooting the computer to Recovery Console and using FIXMBR will remove the virus and correct the problem.  One WARNING that should be mentioned is that dual boot systems where you have more than one bootable operating system on a hard drive can be affected so that you lose the ability to boot the alternate operating system.  You might want to backup the MBR record first just so you can restore it if needed.  I also have a FIXMBR YouTube video you might find helpful.

FIXMBR

The FIXMBR website has some additional articles you might find useful.

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