Linux dd command

Top Tip: A tool for fixing the MBR?

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Question from vmelkon "yesterday, I installed Red Hat 8 on my triple boot WinNT4, WinXP, Win2000 machine, hopefully to make it quad bootable.

Unfortunatly it didn't work. The linux booter (Grub I think) only gave 2 options : red hat or DOS and when I chose DOS it gave some kind of error message in text mode (IO disk error 25), so my Windows was dead.

I decided to start by installing Win2000. I booted from the CD, started to reinstall and finally it rebooted. Instead of continuing with the boot process, Grub took over and I was back into Linux.

Starting to get panicky .... finally I decided to mirror the WinXP, win2000 partitions, and then procede with a utility that write 00000 on the entire drive. Then I reinstalled both OSes, then copy the mirror backups back and finally, everything was restored.

Try to guess how much time all this took?

Is there some tool that could fix a MBR (master boot record).

I'm not sure why quad boot didn't work. I have installed linux along side with windows previously. "

Answer from burninbush "Yeah, I've run into that lately, too -- the win2k repair install doesn't give you the opportunity to fix the mbr until after it reboots -- so you're dumped back into the Linux booter. Join the happy crowd of people who have been screwed by Lilo & Grub [sounds like a Disney cartoon]

One way to end-run this is with a 98 boot diskette; run an fdisk /mbr command, which may get you back to being able to boot at least one of the windows, or at the least it'll kill grub/ lilo dead.

So ... ALWAYS take the opportunity to make a boot diskette when Linux gives you that option. If that routine works [good luck there, too] then you'll be able to get back into Linux, at least, and there you may find -- in /boot -- a copy of the mbr that was replaced. So you can then use dd to put it back. Otherwise, you can often boot off the Linux install cd -- if you can get to a command prompt, that's enough to do the dd fix. Any of the Linux live cd's would work for this.

I think the linux booters' config routines just assume that any primary windows part is bootable. "

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