Master boot record

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Editing/replacing MBR contents

The Master Boot Record (MBR) is a 512 byte space created alongside the primary partition of a drive. Malware-infected records cannot be removed during a simple format; it must be overwritten completely with the following example command,


 dd if=/dev/zero of=/dev/sdb bs=446 count=1

Boot Record Fix

Please note that the following fixes are for instances of a single operating system installation. Do not attempt the instructions below with a computer running more than one operating system.

Windows XP

Boot into the Windows XP disc. At the prompt, "To repair a Windows XP installation using recovery console" press R, then use the fixmbr command at the prompt and confirm with a Y.

Vista/7

Boot into the Windows Vista or 7 disc. When available, click on the command prompt and enter, bootrec /FixMbr at the prompt and follow the instructions.

External Links