The boot sector is the first sector on a floppy disk or it is the first sector of a hard disk partition. It contains vital information about the disk or partition, such as the number of sectors and a micro program.
When the PC starts up or boot-up, it will attempts to read the boot sector of a disk in drive “A”. If it fails to read drive “A” or because there is no disk, it will attempts to read the boot sector of drive “C”. When a boot sector is attack by virus, it will replace this sector with its own private code and generally will relocate the original boot sector elsewhere on the disk.
Even a non-bootable floppy disk has executable code in its boot sector. This displays the "not bootable" message when the computer attempts to boot from the disk. Therefore, non-bootable floppies can still contain a virus and infect a PC if it is inserted in drive “A” while the PC is in a bootable stage.
FDISK /MBR will not change the code in a hard disk boot sector (as opposed to the partition sector). Most boot sector viruses infect the partition sector of hard disks and floppy disk boot sectors. Most viruses do not infect the boot sector of a hard disk with the exception of the Form virus.
A missing or corrupt ntldr ntdetect.com files may also rendered the XP unbootable.
To replace a damaged ntldr and ntdetect.com you can copy fresh files from the XP CD using the COPY command.
Boot with the XP CD and enter the Recovery Console. At the Command Prompt type the following (where "X" is your CD-Rom drive letter). The following command will overwrite the old files.
COPY X:\i386\NTLDR C:
COPY X:\i386\NTDETECT.COM C:
If XP won't start it may be due to a damaged boot sector. To repair a damaged Boot Sector at the command prompt type FIXBOOT and press Enter. Then answer "Y"
Contents
- Introduction
- Windows Registry Basic
- Creating Backup of Windows Registry
- How to Install Windows XP on your CD/DVD/Pen drive
- How to quickly reset all the System Restore points
- How to Repair Install XP without data loss
- Installing the Recovery Console
- Giving Recovery Console access to all directories
- How to Repair a corrupt or damage Boot Sector
- Can't Start Windows XP
- "NTLDR is missing" error message
- Removing invalid entries from Add or Remove Programs
- Change the Registered Owner and Organization in the registry
- Remove or modify the arrow used on shortcuts
- How to delete a zero byte file that cannot be deleted in windows
- Fixing Windows XP forgets my folder view settings
- Jump to a registry key directly
- Disable the Windows XP Splash Screen / logo at startup
- Change the Windows Logon screen background color
- How To Change the Windows Logon Screen Saver
- Stop long delay in My Computer
- How to Use Driver Verifier to Troubleshoot Windows Drivers
- What is Spyware and Adware?
- Do your Windows need a Registry Repair Software?
- Six Criteria of a good registry repair software