Hi

I was running win xp on my sony vaio laptop and it started not to boot because it can not read the boot data part of the hard disk i suppose.
unbootable ...etc.. is written on the blue screen when i try to boot.

So I got a knoppix 3.4 cd and boot from cd rom, to rescue my data in the hard drive. I connected the external Hard disk which is wd and with fat32 system it appears on the desktop with the name sda1, so it is fine, i can read the files inside. It is automatically mounted I think.

But there is no hard drive hda (ntfs) referring to my main hard disk shows up on desktop. When I write

"fdisk -l" on knoppix shell console, the following is found:

automatically
sda hard drive found by knoppix (the external usb hard drive)

there is no hda showing up for this command.

For the command "df" the sda1 external hdd is showing up again but there is no hda again.

I thought my hard drive is corrupted so badly thats why it is not recognized, but I tried the same things on another laptop and the results are the same.

Can anyone please help me to detect my hard disk with knoppix?
Anything will help, thanks a lot..

i would try a different live CD distro like Slax or R.I.P. (Rescue is Possible)...

It does sound like the hard drive crapped out completely, but one should do a process of elimination to make sure.

1: Check the bios to make sure the drive shows up there.

2: If it does not show up in the bios also, check wires and connections used to power the drive and move data for loose connections, power supply failure and/or bad cables.

3: You can connect another drive in it's place to see if the laptop sees it. If it does, try the original again, if it is still not seen and appears not to spin up, it is more than likely shot.

4: You can try the drive in another laptop, computer or USB externel hard drive enclosure, (sounds like you might have done this already), to see if it spins up or is recognized which would narrow the search for bad hardware in the original laptop, it may not boot up, but if it spins up it should be recognized by a live CD at least.

A quick thing to try is reseating the laptop's harddrive. You should see at least a device for the drive even if the contents are corrupt. Newer kernels don't use /dev/hdX anymore. You will see an ATA drive as /dev/sdX when using these kernels. If you do see a device for the drive, you might try:
sudo file -s /dev/<device>

On my Laptop it says this:
If you installed Linux on this machine, there may be a backup of the MBR in /boot/ or /boot/grub. The first 244 bytes are the boot loader part. The rest include the partition information.
You will need to see the device before restoring a bad MBR however.
To restore the first part of the mbr:
dd if=/boot/grub/<mbr-backup-file> of=/dev/<device> bs=244 count=1

To restore the entire MBR including partition tables:
dd if=/boot/grub/<mbr-backup-file> of=/dev/<device> bs=256 count=1

Linux is not installed on the laptop, it was running win xp. I tried it on other working laptops as well but the only hard drive found is the external hdd that is connected by usb, and that one is a sda1 partition. Other than that there is no hdd found sdX or hdX.

I tried the command

"sudo file -s /dev/sda" without connecting the external hdd and the
result is: "/dev/sda: no read permission"

When I connect the external hdd result is: "/dev/sda: x86 boot sector"

"sudo file -s /dev/hda"
result----> "/dev/hda: ERROR: cannot read '/dev/hda'(Input/output error)"

I tried the same commands on another laptop which is working normally and exactly the same results showed up again.

Is there a command to block the automatic introduction of devices?
and is there a command to introduce devices manually? so that i can introduce the hdd s manually.

thanks for any help

After booting Linux from a live distro, enter "dmesg" in linux and read through the boot messages. If both windows and Linux are telling you the same thing; that the drive is bad, that is probably what the problem is.

I don't think using the mknod command to create a /dev/hda1 device would help. You need to get into the bios and see if the device is even detected by the bios. Do what JuniorHacker recommended in post #3. It sounds like the drive or the drive controller is bad.

On most laptops, you can open a panel on the bottom of the laptop and the drive will pull out. You might try pulling it out, blowing any dust from the contacts on the drive and the connector, and reinsert it. ( Be certain the Laptop is powered off; don't use a lot of spit! )