How to recover data and reverse the operation done by dd command

[getasif]

Hello there

I have done a mistake, since my laptop wasn't recognizing the bootable Windows Xp CD i tried executing this command in Linux to clear the

Grub bootloader hoping that I would be able to install the Windows XP and the command is this

dd if=/dev/zero of=/dev/sda bs=512 count=1

I got the above command on a forum (icrontic.com/forum/showthread.php?t=39459 )since I was desperate to install XP I executed it thinking that it would erase the bootloader and not the driver partitions.

After rebooting the Win xp cd booted but the partitions were all gone ...I know this is a very dangerous command but is there any way to reverse and get at least the partitions back as before.

I have some important data - around 8gb and that is what I am concerned about.I have left the laptop as it is hoping that there would be a way to reverse back the harm done by the above command I executed on linux.

I am using RHEL 5.5 Server Tikanga

Please help and please let me know if I can recover the data I have lost


Thanks and regards

[oz]

dd if=/dev/zero of=/dev/sda bs=512 count=1

After rebooting the Win xp cd booted but the partitions were all gone ...I know this is a very dangerous command but is there any way to reverse and get at least the partitions back as before.

Hello

Try running TestDisk on the drive to see if it can recover your partitions:

TestDisk - CGSecurity

[atreyu]

Agreed, TestDisk has saved my bacon - it comes with the System Rescue CD for your convenience.

[yancek]

You wiped the partition table along with Grub from the mbr. If you had replaced the "512" with "446" you would still have the partition table.
You should still have your data and I agree with the above posters on the software to use.