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-   -   hosed MBR (https://www.linuxquestions.org/questions/linux-software-2/hosed-mbr-26460/)

lacrimae 07-24-2002 09:02 AM

hosed MBR
 
Well. Virus related....norton antivirus in windows "restored " my MBR, which of course had grub on it which of course was hosed.

My ignorance further compounded my original decisions on handling this when I tried to repartition/reinstall the os'es. :tisk: Dos disk doesn't load , fdisk rescue disk does not load so I cannot fdisk...parted wont format partitions, so I have a fat16 partition from my thankfully successful red hat install (THAT works fine )
that wont take a ghost image or the recovery cd.

I have used the RH7.2 to get various rescue floppies, and I format those to be msdos, and I get an "non system disk error" message. Cant seem to digm out of this mbr issue to fdisk and install windows. (Which I want.)

I am using grub now, I have a dos partition which I said is useless....I have no Idea how to proceed.

I have spent ten hours on the internet searching and trying stuff before I posted this.

Ideas? thanks for any suggestions

fatgod 07-24-2002 09:49 AM

Don't you have your windows CD? can you not just boot off it and start the reinstallaion?

But anyway you can restore a MBR to windowsness by starting an MS OS from a floppy (or CD) that has fdisk on it.

You type...

FDISK /MBR

at the prompt.

lacrimae 07-24-2002 10:05 AM

>so I have a fat16 partition from my thankfully successful red hat >install (THAT works fine )
>that wont take a ghost image or the recovery cd.

>I get an "non system disk error" message. Cant seem to digm >out of this mbr issue to fdisk and install windows.

I'm sorry if that was not clear...but the fdisk /mbr command cant be issued if I cannot get the floppy to boot and give me a prompt. I cannot get there. Parted did not work, the red hat fdisk did not work....I have tried the level one solutions. Thank you for your suggestion, however, I bet I am in fact overlooking something simple.

sarin 07-24-2002 10:09 AM

Did you check the boot sequence?. Is floppy the first boot device?
--Sarin

jetblackz 07-24-2002 10:13 AM

It sounds like MBR was screwed by some partitioning utility. NU backs up your MBR & crucial files at the time of install. So whatever change you made to MBR WILL be lost.

I'm guessing your BIOS setup is uncommon. Go check it out and make dead sure your boot order is: floppy> cdrom> hd1.

lacrimae 07-24-2002 11:01 AM

oops---well the tricky thing is floppys will boot---norton ghost, dos boots but gives errors because it doesn't have sys files available. just not the rescue/fdisk floppy.
I am thinking I gotta get one made on a windows machine although I made it on a msdos formatted floppy , in Red Hat?
That's the part that is sending me in circles over and over.
Plus I can RUN THE RECOVERY CD, yet never load the os it installed, and a windows 98 boot floppy will not load it , nor will grub if I try that.

I will not give up! But I need your heads!

jglen490 07-24-2002 11:58 AM

If you can get to www.bootdisk.com then you can download a bootable DOS disk. Get a recent version and it should have fdisk on it that will run the /mbr option.

Simply formatting a diskette in DOS format, of course, does not put the required system files on it and you can't get to the required system files if you can't get to your Windoze space. Whew, talk about Catch 22 :D !!

lacrimae 07-24-2002 12:07 PM

Thats the very rescue disk I tried!! That is the one I put on the floppy. That very one. Plus another one from www.radified.com

jglen490 07-24-2002 02:18 PM

So it comes down to:

You have set your BIOS to boot FIRST from the floppy drive. Your system refuses to boot a valid floppy diskette that has the proper MS-DOS system files on it. And because of that you can't restore the MBR to its former glory. You also are unable to use any OS's install CD in a rescue process -- and that includes the Linux CD. You can't get to either OS (Win or Linux). Because you can't get into Linux, you can't reinstall Grub. Because you can't get into either Win or DOS, you can't fix your MBR problem. And all of this because Norton Antivirus detected that the MBR had been altered and proceeded to "fix" it.

Does that pretty well cover it?

One more try. If your BIOS is set to boot FIRST from the floppy, get a copy of Tom's Linux boot disk and try to get to Linux. From there you may be able to get back into your Linux space on the hard drive and re-install Grub.

Dutch3 07-24-2002 02:59 PM

For what its worth, if you manage to get back into a bootable system and you find your partition table is corrupted - and Windo$e fdisk wont recognise your Linux partition, download aefdisk from www.aefdisk.com.

This program lets you manage your partition table, including deleting it completely so you can start from scratch again. When I needed to rearrange my drive and couldn't use fdisk - this program saved the day.

If all else fails, of course.

BTW, have you tried the boot disk from a similar Windo$e system option yet?


Dutch

lacrimae 07-25-2002 07:08 AM

:rolleyes:
SO i got it all going...I restored the windows ghost image to the FAT 16 partition I made with red hat's disk druid. (If you don't know, that is all it will do.)

I set up grub in linux boot partition, and pointed it to windows as normal, and it booted into safe mode once, then after that ok.

I don't consider this permanent, but maybe I can get the MBR restored now that I have gotten this far....I wonder why the computer sees the grub on /dev/hda2 but not much else? I need to do less hurried reading now I guess.


I post this just so you know...thanks again for the tips.

madcrutch 07-27-2002 11:14 PM

If you just want to start from scratch or you run into this again, try these free seagate tools. Disk wizard and Seatools. below is tha URL. There are utilities to blow away a drive so you can start from scratch. It also has a partition ultility and disk diagnostic tools. You can load the program on a windows PC and it will create boot floppies with the selected tools on them.

http://www.linux.org/docs/ldp/howto/...WTO/a1483.html


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