124. Checking your disks
By Andrew D. Wright
I'm having a problem when I run Disk Defragmenter. I get a message that
says corrupt file, please run the chkdsk utility. I've asked different
people and they have no idea.
Beaver Bank, N.S.
One of our very cool Chebucto Mousepads is in the mail to you, Arthur, for
On Windows computers files stored on the hard drive can fragment, or be
broken into smaller pieces that are stored on different parts of the hard
drive. This happens all the time as Windows moves files around and writes
the new files in the empty spaces left by deleted ones.
Running Disk Defragmenter every two or three weeks puts the pieces of
files together in a more efficient pattern on the hard drive so the
computer can read them faster. In Windows XP, go to the Windows Start
button then All Programs then Accessories then System Tools to find Disk
Sometimes though things don't work that smoothly. Files and folders on a
hard drive can become corrupted, which means part of the recorded data on
the hard drive has been messed up or is missing.
Disk Defragmenter can't risk moving files when it can't be sure what parts
of the hard drive are available. To fix this you would run chkdsk, a
program that comes with Windows.
In Windows XP run chkdsk by clicking the Start button then click on My
Computer. In the new window right-click on your C: drive then select
Properties. Click the Tools tab and click the Check Now button.
In the new window that opens click the top checkbox to do a scan and
repair of the files and their indexes. Click the bottom button as well to
add a full physical scan of the hard drive. The full scan takes a lot
longer depending on the size and condition of the hard drive.
The computer will then need to restart. After the Windows splash screen
has loaded chkdsk will come up and tell you to press a key within ten
seconds if you want to cancel it. Don't press any keys and it will begin
scanning your disk.
In the case where a hard drive has developed a bad sector, chkdsk would
attempt to retrieve the corrupted data and write it to a good part of the
hard drive. It would then mark the bad sector as off-limits for any
further writing. It can't physically repair the disk.
In cases where data is scrambled or missing, chkdsk would turn any
unidentified file fragments into new files with a .CHK filename. You could
open these files with a text editor program like Notepad to get some idea
what had been over-written. It is sometimes possible to recover text from
a truncated original file.
File scan and repair usually takes less than five minutes to deal with
minor file errors while full scans can take up to a few hours.
It's a good idea to run chkdsk every now and again to keep file errors to
a minimum and check for bad sectors on the hard drive.
Still running Windows 95, 98 or Me? First stop any excess running
programs. Press the Ctrl, Alt and Del buttons at the same time to bring up
Task Manager then one by one End Task until only Explorer and Systray
remain on the list.
Go to Start then Programs then Accessories then System Tools and click on
Scandisk. It offers a standard file system scan and thorough hard drive
scan. Click the checkbox to automatically fix file errors and let it run
undisturbed. After it has finished come back and restart the computer.
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Originally published 25 January 2008