Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I got a harddisk from my friend, it maybe broken, so I need to save any remaining data which can be saved.

I can see the drives, but when copy some files, the computer said they are bad and rereadable(not exact phrase).

Then I installed some software, thinking maybe they can check whether and which files are corrupted, then I rebooted the pc.

After the shutdown of the pc, the computer started a disk scan on the harddisk, and I am not awared of any prompt from the pc. Now the scan is running and takes some time to finished.

At the mean time, it found some files and folder are in the bad sector. Then it said the files are replaced by null. And it said it removed a folder because it is entirely unreadable. Actually I don't know what does it mean, **so my question is - What does the scan do when it encounter bad files and folders? Are there any chance I can save the data, maybe with any other software?

By the way, can I stop the scan? I tried to press Esc, Alt+Ctrl+Del, don't work.**

share|improve this question
I pressed the power button because the scan held at 58% and not increase any more. – lamwaiman1988 Jun 11 '11 at 16:31
Duplicates "Bios/Windows cannot detect my bad harddisk". – JdeBP Jun 13 '11 at 11:31

You can try CTRL+BREAK to stop the execution of scandisk command.

After that, I recommend you using Roadkil's Unstoppable Copier to recover your readable files.

Roadkil's Unstoppable Copier recovers files from disks with physical damage. Allows you to copy files from disks with problems such as bad sectors, scratches or that just give errors when reading data. The program will attempt to recover every readable piece of a file and put the pieces together. Using this method most types of files can be made useable even if some parts of the file were not recoverable in the end.

share|improve this answer
This looks like exactly what I need for recovering as much as possible of CSV (text) files from a laptop that was dropped. However, it doesn't run from the Recovery Command Prompt (Startup Repair advanced recovery options). Any other suggestions? – Ben Voigt May 18 '12 at 15:35

"[...] it found some files and folder are in the bad sector. Then it said the files are replaced by null. And it said it removed a folder because it is entirely unreadable.[...] What does the scan do when it encounter bad files and folders? Are there any chance I can save the data, maybe with any other software?"

The scan remaps that bad sector to a good but empty one, the data in that sector is lost. If that sector was part of a file, folder, directory listing etc that logical object now has a bunch of 0 bytes somewhere in the middle, which may lead to subsequent logical errors. Then programs like checkdsk will try to correct those errors, e.g. by erasing the damaged directory entry for a folder (in that case your folder is logically gone, although most of its data are still somewhere on the disk).

It's probably too late now, because you have already let all kinds of software do its 'repairs'.

The best procedure in these cases is:

1) Do not shut down/reboot any more than necessary. If the bad spots are in critical sectors at the beginning of the disk the system may not boot up again.

2) Optionally, try to make an image of the entire disk or in one way or another pull all the important data from the disk. There's lots of variations on how you can do this, but whatever methode you choose, read only!. Do not write to the disk. Pulling it out of your computer and putting it in another computer as a non-primary disk is a good way to prevent software (the OS) from automatically writing to it.

3) Buy a copy of Spinrite and run that on the damaged disk. SR will not just reallocate the bad sectors, but it will keep reading the damaged sectors thousands of times, slightly re-adjusting the disk heads, in an attempt to (statistically) reconstruct the data that was in the bad sector, then write that data to the new sector. Very often this leads to a full recovery without errors.

4) Finally run software that does logical checks on the disk structure, like checkdsk. This could veryy well not find any errors after step 3.

While running, SR will also check for an overheating disk or other potential problems.

Bye Jan

share|improve this answer

If the disk is bad, and may die, you need to do as little to it as possible for fear of making it worse,and having it die totally. You do not want to do anything directly to that disk except copy it, and then work from the new disk.

If you can, get a DOS boot disk of Ghost 2003, and start it with the following command

ghost -ia -fro

This will image the entire disk sector-by sector and ignore bad sectors. You can then attach this cloned disk as a secondary disk to a system and suck the data off it. I don't know if Clonezilla, which is free, will ignore bad sectors or do a sector-by-sector copy.

share|improve this answer
windows + bios cannot detect the harddisk now. What can I do? – lamwaiman1988 Jun 11 '11 at 15:24
@gunbuster363, then how is it being scanned? – Synetech Jun 11 '11 at 16:26
Never mind, this question is from before the new one about the disk not being detected anymore. – Synetech Jun 11 '11 at 16:36
Now I know that it maybe I causing the death of the harddisk by pressing the power button. – lamwaiman1988 Jun 12 '11 at 5:24

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.