81 replies to this topic 5 votes

[markjensen]

Catharsis, on Apr 10 2006, 17:43, said:

Hmm, that must be if you've installed Linux in a VERY specific way, because now I can't boot into either OS. Wonderful.

No. It is very general, as it restores the Microsoft MBR to the hard drive.

Chances are that some other action has corrupted your partitions if this doesn't work.

[QuarterSwede]

All I know is that that method has never worked for me.

[Banzai]

i aint got the recovery console on my xp cd

[markjensen]

Well, here is a method that will work, if you can boot Linux (installed or LiveCD, it doesn't matter).

The "code" part of the MBR is the first 446 bytes of the hard drive. If you can get that as a file, then you use the command (as root):
dd if=mbr.bin of=/dev/hda bs=446 count=1

Now, all we need is some nice soul with XP and a LiveCD to grab the 446 bytes from his XP box and post it here, so others can use it to write to their MBR.

That eliminates any problems with booting the XP CD and getting to recovery console, or booting from a floppy from bootdisk.com.

[Keisugo]

well I have tried the fixmbr in the windows recovery console, but wasn't sure if I had screwed up beacuse after typing that in, installation then rebooted right into the windows xp install. Now even if i try to stop it midway, the installation pop up again even if I reboot. Basically, my concern is if my files will still be avaible to me besides the fact that the windows installation is installnig windows xp again

[markjensen]

Yes (if I understand you correctly).

Your Linux partition(s) will be there, untouched. The fixmbr just reset the Windows bootloader to its Microsoft-default settings. You can do a grub-install to get the ability to use GRUB to boot back into Linux.

Use a LiveCD to browse around and verify your data is untouched for yourself.

[+ViperAFK]

after i do the fdisk / mbr how do i reboot from there without having to turn off the PC? (cause that doesnt fix the bootloader if you do that)

[markjensen]

It is fdisk /mbr (no space in the "/mbr" part), or fixmbr. That might be part of the problem.

That fixes the MBR. If for some (non-Linux) reason, your boot.ini file is in need of repair (Linux doesn't touch NTFS, so it could not have modified it*), you can do a fixboot, and I believe that it will fix the boot.ini and NTLDR for you.


* Technically Linux can write to your NTFS partition, but it would take several deliberate actions on your part.

[Kraftman]

markjensen : Linux + NTFS write = kernel recompile. Is it stable and safe to write to an NTFS partition in Linux? This would be hardcore BitTorrent downloading with every second file access kinda thing.

[markjensen]

Honestly, I don't know.

Conventional wisdom has been when I started using Linux that it was experimental and not recommended.

I don't know how much native NTFS has improved since then. Also, CaptiveNTFS made its debut a few years ago, and that uses Windows' own NTFS.SYS file to 'understand' the NTFS filesystem. I have heard it works, but is a bit more sluggish.

You will always be safe writing to a Linux native filesystem, or FAT, so that is what I would probably recommend.

[+ViperAFK]

well what basicaly happens with me is i did sepll it right, i typed "fdisk /mbr" and it said "are you sure you want to write a new mbr?" and i hit enter, than it just says it again and again, so i couldnt figure out how to restart my pc from there so i hat to hit th power and it was still GRUB.

[markjensen]

Are you supposed to hit ENTER or answer 'yes'? It certainly seems that your XP Recovery Console isn't re-writing the MBR!=...

[+ViperAFK]

well, it doesnt say what to do, and it only lets me type one letter

[+littleneutrino]

the way i got my bootloader back is put in the xp disk and then run the recovery console and type in Fixmbr or fdisk\mbr

[+ViperAFK]

well that is what i did, like i said it just keeps asking me if i want to write a new one and doesnt do it.