What does CHKDSK/F actually do? Today I discovered that I had a lot of unreadable segments on my hard drive, so after trying to unsuccessfully run scandisk.exe I remembered the DOS command chkdsk/f from the old days. I'm amazed that I had to go back to an old DOS command to repair my hard drive and there was nothing in Windows that helped me out.

Pleas explain to me what chkdsk/f actually does besides repair bad sectors? or is that basically it? Are there any other DOS commands that you still find helpful in Windows? If so, list them and tell me when they would come in handy.

There was a DOS partitioning command that I used to find helpful, now I can't remember what it was.

First I should point out that ChkDsk doesn't repair bad sectors -- they are almost by definition unrepairable.

Both DOS and Windows can sometimes fail to return a cluster (allocation unit) to use. A crash requiring a reset can also cause this. The clusters are marked "in use" in the FAT, but are no longer part of any file.

ChkDsk /F (fix) can identify these "lost" clusters. It you so choose, ChkDsk will save the data in the clusters as files (with filenames of FILExxxx.CHK), then mark the clusters as available.

You should try to determine why ScanDisk for Windows could not run. Very often, some other process running in the background is interfering with the program. You can start Windows in Safe Mode to run ScanDisk (the preferred method). ScanDisk for Windows can detect and resolve a greater variety of problems than ScanDisk for DOS and ChkDsk combined.

TomGL2, could there still be some physically bad sectors on my hard drive, like actual surface damage? or was it just data damage since chkdsk/f actually fixed the problem. I will still run scan disk as you prescribed.

I've been concerned that there may have been some physical damage to my HD because of the resent heat. I've lost more than one hard drive on extremely hot days...

You may wish to look at Steve Gibson's SpinRite 5.0. I have used this on my 5 year old machine for a couple of years now, with good success. On my machine it takes about 36 hours of continuous running to complete.

Steve Gibson - GRC

Dwight

Thanks Dwight, I looked into it, unfortunately it doesn't support my NTFS file system.

You are hopefully using the NTFS version of ChkDsk for Windows NT, 2000, or XP. Don't use the DOS version at all.

If you're running ChkDsk without specifying any switches, the program may report errors which do not really exist. ChkDsk /F /R will check the entire disk, not just the areas in use. Symantec and OnTrack likely have NTFS disk repair tools available.

In future, you should always mention the version of Windows you're running, and other pertinent information (like the NTFS on the drive).

I know all about that. I think the drive is just toast. I pulled it out of my computer today and the thing was extremely hot to the touch, beyond normal. The hard drive that has all of my system files on it wasn't hot at all... Just a little warm.

It's a bummer because this was my big hard drive and it had all of my MP3's on it. I lost a lot of stuff. Gee, I sure wish I had made backups;)

It looks like I'm in the market for a new hard drive... I guess I'll check out that AnswerPool gift shop...

Billmasters:

Today, you have learned a valuable lesson in regards to backing up your data.

With the size of just about everything being in the Gigabyte range, it seems that it takes forever to restore it all from your OS Diskette & all the other programs that you have on your computer.

I just lost my CD-ROM drive, it just froze & refused to open.

When I went to CompUSA I purchased & had them install a Memorex 52x24x52 CR-RW Drive. Now I have the capability to save all of the data presently on my Hard Drive on five 700-Mb CW-RW Diskettes. Is this ever a relief when I have to reinstall the entire hard Drive. In the past it has taken me about one full day to do this. Now it takes me about one hour.

I was saving data on 3 1/2-inch Floppies & 250-Mb ZIP Diskettes. As you can well imagine, it took forever to restore the data. The only reason I did not use my OS CD-ROM Diskette is because it Reformatted my Hard Disk before it installed the OS. In addition, you see, I still had all the other programs that I have on my computer to resinstall.

I would recommend that you do the same thing if you have problems with your Hard Drive, in the future. That way you would have all of your MP3's backed up, in addition to everything else.

To TomGL2:

In your reply to Billmasters on your post of
07-22-02 @ 03:10 you specified for billmasters to run a:

Chkdsk/F/R

On my Chkdsk/? it has an /F & an /V.

V on my computer specifies:

'Displays the full path and name of every file on the disk'.

I have Win 98 2nd Edition. Could this be different on other Win OS?

Good day, Donald. Bill must be using Windows NT, 2000, or XP (hence the NTFS), and Chkdsk on those OSes is much more like Scandskw on Win 9x/ME.

The Chkdsk included With Windows 98 is an old DOS utility. It is a simple, limited program which often causes more damage than it fixes. For instance, Chkdsk almost always modifies the directories to agree with the FAT, even when the FAT is wrong. Because the previously correct directory data is lost, other utilities cannot repair the FAT afterward.

Is is very important to first use Chkdsk without the /F parameter to first determine the kind of damage and its extent, but my recommendation is to never use Chkdsk's repair function.