How to copy dummy file onto defect hard disk sector and block it?


Extraordinary Member
On one of my (older) computers there is a defect sector on the hard disk.
Checking the surface of the hard disk shows a red square for it.
It seems to me that all the "usual" reserve sectors are already in use.
Every thing else works on this computer. No unusual noise comes from the hard disk.

Since I do not use this computer very often I don't want to replace the hard disk and reinstall all the stuff on it.

In order to avoid that Win7 copies some important files exactly on this sector I am thinking about to copy a dummy files exactly onto this bad sector and write-protect it.
So I will have a blocker for further other usage of it.

Does this work?

How can I identify the exact number of this bad sector and copy a dummy file exactly on this sector?



Fantastic Member
Microsoft MVP
If it is a bad sector, it will already be marked in the drive's tables as unusable and Windows will not try to write to or read from it.

I recommend you just open an elevated command prompt, then run chkdsk /r (note the space before the slash) on the drive. This will analyze every sector, and if able, remove any data from any bad sectors, then ensure the bad sector is marked as unusable.


Fantastic Member
Microsoft MVP
As long as you make sure you select "full" - not "Quick" - formatting. But of course, if there is any data on the drive you don't want lost, formatting would not be a good idea unless you copy that data off first.


Windows Forum Team
Staff member
For chkdsk /f will find errors and fix them and /r will find bad sectors and try to recover that data. It isn't documented whether or not it will mark them as bad though.


Fantastic Member
Microsoft MVP
So "chkdsk /f /r" alone (without re-formating the disk) does not help?
Sure it does. And again, /f with /r adds nothing.

If you open a command prompt and enter chkdsk /? you will see that /f "fixes errors on the disk", and that /r "Locates bad sectors and recovers readable information" but it also "(implies /F...)." That means running with the /r switch does everything /f does, but more. If you enter chkdsk /r /f, the /f will simply be ignored.

And for sure chkdsk with the /r or the /f switch will indeed mark any unrepairable sectors it finds as bad so the drive will not attempt to use those locations again.

If you run chkdsk by itself, with no switches, it just checks the disk and reports any errors. It will not fix any errors. And note fixing again implies actually fixing the bad sector and/or marking it as bad in the file tables if it cannot be fixed.

There is no need to run chkdsk and format. You will just be wasting your time and increasing wear and tear on the disk.

And again, this only applies to the "Full format" option. "Quick format" can only be run on a disk that has previously be formatted and it only clears the file tables. It does not even touch any of the data storage locations.