Hardware

I had ACER aspiron one netbook with dual bootable (Windows XP and Debian). Recently I found XP is messy and Debian has new version published. I plan to recover XP and install new version of Debian. But I failed to recover XP from Hidden Partition.

I thought it is because I install GRUB in the harddrive which make the hidden partition not bootable. I hope I can remove the part. I remember I did this before using DOS command "fdisk /mbr", but I couldn't find fdisk any more. I want to see if there exist LINUX command equivalent to DOS command "fdisk /mbr". Terrible thing happens...

There exist one webpage talk about

dd if=/dev/sda of=/root/backup.bin count=1 bs=512
dd if=/dev/zero of=/dev/sda count=1 bs=512

I did so since I thought the first command is backup. But, but, the second command erase FAT. So that the machine can't find my /root folder in LINUX. Actually no partitions can be found in my hard drive!

Is there any way I can get FAT back? Or only solution is, ignore all data in the drive and install OS again?

Thanks in advance of any suggestions.

First three rules of data recovery are:
I have no idea if your data even still exists at this point, and would need shell access and a hex editor to find out. fdisk -l in a Linux recovery cd might be a good start, it'll show what your partition table is right now.

Thank you for your information.

Currently I just leave the netbook alone. I hope I can somehow find solution before I format the whole disk.

I have a bootable USB flash memory with GRUB such that I could boot the netbook in Windows, Debian. Now each part just tell me that the partition doesn't exist. It should be, because the Table of primary partitions are all zero now. I hope there exists one way such that I can get /root/backup.bin file from the disk and recover the Table of primary partitions...

You might be able to roughly find the beginning of the partition by looking for FAT32 in a hex editor. Compare how that looks to a real working FAT32 partition on a flashdrive or something to make it more precise. How to find the end I'm less sure, and how to translate that into a working partition layout, I'm also less sure, but fdisk -u may help as that will help you get it working in sectors instead of cylinders... I don't suppose you know what fdisk -l should show?

Corona688, Thank you for quick response.

Currently I just have grub with command grub>. Maybe I can make USB flush with base linux to run the command fdisk -l /dev/sda. But I believe the result should be the disk is not partitioned yet since the Table of primary partitions are all zeroes now...

I just read Wikipedia about MBR: http at en.wikipedia.org wiki Master_boot_record
and dd(UNIX): (sorry I can't post URL now, it should be wiki/Dd_(Unix))

You need a rescue CD of some sort to do anything.

You are absolutely right.

When I bought this netbook, there didn't exist rescue CD, but the first primary partition is Hidden recovery disk. I had erased the secondary primary partition (which is original C: drive), create a smaller secondary partition (new C: drive) and third partition as extended partition...