Copy/Save/Restore That MBR

The MBR— Master Boot Record— is the Rosetta Stone that unlocks the contents of your hard drive: It’s usually the first sector of a hard drive, and contains the "partition table" (a record of how the hard drive’s files are set up, including where the operating system software is located) and the initial boot loader that the BIOS uses to launch the actual operating system. When the MBR is messed up, your PC isn’t going to do much:

Fred: Just yesterday morning I locked horns with the devil. DriveImage5 would not let me run it from windows (where it boots to DOS and back). When running from floppies it told me to eat a big one. HUH?!?

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[Two weeks earlier] I received a 250gig drive. I put it in my hotrod Dell main machine. I’ve had goofy problems with a 200gig that never did make sense.

Windows Disk Management and Partition Magic 8 both saw the drive as 128gig. Huh? I’ll spare you the blow-by-blow but it turns out my BIOS wasn’t supporting the large drives. A BIOS flash upgrade cures that hours into the problem. But in the mean time I used the CD that came with the Maxtor drive. Along the way it kept asking "I’m gonna do this, OK?" along the path of preparing the new drive. Then AFTER the final step it informed me it had installed software on my boot drive. What?  I didn’t want it that way, AND the drive was destined for another machine anyway.

The beast wedged itself in before Windows altogether. So I went about uninstalling it. After lots of Googling I found where the buried uninstall option was. Even then it took me 5 minutes to get it to work correctly. Well not correctly as you’ll read later, but "at all".

I got the problem of formatting the disk correctly straightened out:
1) Upgrade motherboard BIOS
2) Set an obscure registry entry allowing Win2K to see 128g+ drives (long time spent discovering that thorn as well). Read that whole battle to at least know it exists:
3) Now format & partition under Win2K or Partition Magic.

[Now,] DriveImage5 would not let me run it from windows (where it boots to DOS and back). When running from floppies it told me to eat a big one. The message was to the effect "Disk Manager" was found on the disk so DriveImage wouldn’t tough it and existed to DOS! But wait, I had removed Disk Manager!

Long story shortish: I had to recreate the "Master Boot Record" on the boot drive for Win2K . You used to be able to fix that with "fdisk /mbr" but no, not in Win2K. There you have to use the command "fixmbr", while booted into the "Recovery Console" from the installation CD. [note: XP works the same way]

Yikes. Through those two sessions I spent a lot of time at wits end, and I consider myself an above average user. (OK, I’m attempting to be humble but I choked on the word "user").

I haven’t done it yet but I plan to get a program that copies the Master Boot Record (MBR) to a file. Run that before imaging my disk. That way I’ll have my MBR instead of going through brain surgery. —Robert Humphrey

Once you know about them, the FIXMBR trick for XP and Win2k ( ) and  FDISK /MBR for Win9x ( ) aren’t too hard to use, but as you discovered, the time to learn about them is before you’re neck-deep in a crisis. <g>

If you want, there also are tools you can use to preserve a copy of the MBR. For example, see "MBRtool" .

MBRtool is not an automatic recovery program but will allow users to prevent dataloss (due to MBR corruption) by backing up the MBR, and offers power users all the power they’ll ever need to ‘mess’ with their MBR. MBRtool is freeware.

Or, there’s a more powerful commercial version called "DiskPatch" :

Did you lose access to your partitions or volumes due to master boot record (MBR) or partition table corruption? … You can probably fix it yourself by using DiskPatch! DiskPatch automatically repairs damaged, corrupt or missing partition tables and boot sectors…

Lots more options, too:

Fred Langa

About Fred Langa

Fred Langa is senior editor. His LangaList Newsletter merged with Windows Secrets on Nov. 16, 2006. Prior to that, Fred was editor of Byte Magazine (1987 to 1991) and editorial director of CMP Media (1991 to 1996), overseeing Windows Magazine and others.