Hi,

I have a maxtor 20GB HD. I had two logical partitions, one Fat32 6GB, and then an ext3(13gb) partition (for linux). I installed Fedora Core 3 linux first. (My first mistake, because I should have installed the win98 OS first.)

Therefore, I realized that I should try turning the Fat32 logical partition into a primary partition. Since Win98 refused to install on it as is.

I am already very wary of Partition Magic, so I figured that I should use the MBRtool, that I just downloaded today (02/12/2005), to backup the MBR of this HD.
I backed up to a file.

I used Partition Magic 7.0, and then tried to turn the Fat32 logical into a primary partition. It failed, saying something about the partition type not being supported. (In hindsight!) Maybe it didn't like the presence of the ext3 partition on the disk.
(Argh! Partition Magic should clarify these error messages by adding "You're screwed! Too late!" as the title of their dialog boxes.)

Grub was fragged. It loaded upon boot and stopped.

Aha! I said. I backedup the MBR! I restored the MBR from floppy file using MBRtool.

Reboot!

Yikes! The computer won't even finish booting! After the BIOS init messages, the HD light just came on and wouldn't stop, and the boot process hung! I tried booting to floppy, so I could use FDISK /MBR. I can't even get to that stage. After the floppy nears boot completion, the HD light goes on, and the computer just hangs. I've tried booting from CD's. Nada. I've tried attaching the HD to another computer as a secondary drive. Same thing.

It seems when an OS tries to find out what HD's it has, it hangs at that point. I can't even run any tools on this HD because I can't boot an OS while the HD is attached.

I've given up about the data. At least I want to save the hardware! The HD was working fine before this mess.

Any ideas? Any help?
If not, then let this be a googled warning to those out there.

Product you are using: mbrtool

Operating system / Service Pack: dos, win98

Size of subject harddisk: 20 GB

Hello,

"Any ideas? Any help? If not, then let this be a googled warning to those out there."

A warning about what exactly? Are you suggesting MBRtool messed up? Because it didn't, you did. MBRtool did what you asked it to, restore the 'old' MBR. Which probably was a mistake in this situation.

PartitionMagic does more than just modifying the MBR when manipulating partitions. So, when PartitionMagic gets interupted, just restoring the MBR hardly ever brings matters back to normal.

You mention Grub. Since I am not very familiar with that bootloader I can not tell for sure if it played a role in this all, but I do not want to exclude that possibility.

Now, Grub aside, this is what I guess happened; when you ask PM to cnvert a logical partition to a primary partition it will have to move the entire partition to make sure it's cylinder alligned. As a result the location of the first EPBR (the start of the extended partition) will be the new location for the boot sector of the partition that's converted to primary partition. The old MBR, of course, doesn't know that! So by restoring that old MBR you have an entry in the partition table for an extended partition that is no longer there. This can cause MS-DOS based operating systems, so Windows 98 and your boot diskettes, to loop/hang when booting.

FreeDOS, which is not MS-DOS, does normally boot in this type of situations. So if we can get that to boot we can clean up the mess you have made. Please, from our downloads page, right column, bottom, grab the FreeDOS boot disk and tell us if it allows you to boot.

--
Kind regards,
Joep

I want to follow up on this.
Sorry if it appeared that I was slamming/blaming the MBRtool.

I thought it was clear it was a series of misteps that almost rendered my 20GB HD useless. I think this should be an important warning to those on the 'net who want to start messing with their partitions and MBR.

Anyway, thanks for your insight that MS-Windoze/DOS systems can't handle toasted MBR's.

I downloaded freedos, and it was indeed able to boot this HD. I also tried a linux boot cd, and this also was able to boot. (Thankfully, there are other OS's to turn to in a pinch, than Microsoft!) And then I used the linux version of FDISK to reinitialize the MBR/Partitions, but I couldn't get back the data (not much personal was on it though anyway.)

Key lessons that I learned:
Using Partition Magic 7.0 on a HD with EXT3 (a newer linux partition) -- beware!!!
Extreme caution mixing MBRtool backups with Partition Magic messes.
Linux and FreeDos was able to boot with an attached HD that has a toasted partition table, but MS-DOS/Windows XP couldn't.

Product you are using: mbrtool

Operating system / Service Pack: dos, win98

Size of subject harddisk: 20 GB

Hello,

"I want to follow up on this.
Sorry if it appeared that I was slamming/blaming the MBRtool."

Okay, sorry! Yes, I was under that impression.

"I downloaded freedos, and it was indeed able to boot this HD. I also tried a linux boot cd, and this also was able to boot. (Thankfully, there are other OS's to turn to in a pinch, than Microsoft!)"

Okay, so all's well again.

--
Kind regards,
Joep