Boot Sector Virus

[Hazy Dusk]

What is the safest way to rebuild a boot sector that has been damaged by a virus? This must be a black science, as I have run into very little information on this subject. Thanks for the input.

[Mole]

1. Make a boot disk from a clean system.

2. Copy FDISK.EXE to the boot disk.

4. Write protect the boot disk.

5. Boot your computer from the disk.

6. Write at command prompt: FDISK /MBR

Your boot record will be rebuild and any viruses residing will be wiped.

[Tuttle]

Mole's suggestion works almost all the time. But if your hard drive has more than 4 partitions or was formatted by a compression program other than Drivespace/Doublespace then DO NOT use fdisk /mbr, it will probably ruin your hd.

[Mole]

If you really had this kind of setup Tuttle describe, a boot sector virus would probably screw up your HD before FDISK anyway.

[Tuttle]

Not necessarily. Most boot sector viruses make a copy of the original boot code and execute it after the virus code. FDISK /MBR writes a standard DOS/Win boot block and destroys any reference to the original code.

I agree that the setup I described is rare, but it does occasionally occur, particularly on drives with something like Linux installed (Win95+Linux+a few swap partitions = 5 or 6).

[Mole]

Hehe, I guess if someone with the knowledge to setup like that manage to get himself infected with a virus, then he really deserves to get screwed up. =P

[jjchip]

What happens when fdisk /mbr doesn't remove the bios warning: "Boot Sector Write!! Virus Continue? (Y/N)" ?
I've deleted all files, tried (unsuccessfully) to repartition/reformat the HD, but still get this message when trying either fdisk alone or with the /mbr switch.
I know this thread is OLD, but it's current for me.
Thanks for any/all advice.


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jj

[sienadingo]

jjChip

I also tried that remedy with no success. Upon typing in FDISK /MBR
I get that same "BootSector Write !!"
message.

If you have solved this problem since, please let me know. I am dying to get this thing working.

Jeff

[joshua_web]

this is solved through disabling the write boot sector option in the bios. You should be on your way. It is best to wipe the hard disk clean using the utilties from the manufacturer's website. eg zero fill utility.