The reason I did that, rather than just give you the answer, is that you probably know far more now about hard drves and chkdsk than you ever did before.
I've just run a read- only check on the hard drive and it says: 'Errors found. CHKDSK cannot continue in read-only mode.' (It also deleted a few 'index entries') Are these 'errors' definitely 'bad sectors?'
chkdsk run in read only mode produces unreliable results
If you run it from a command prompt, it may report errors. Mine does
not but it might some day and here is how Microsoft explains:
....CHKDSK may report that a disk is corrupted even when there is no
real corruption present. This can happen if NTFS happens to modify
areas of the disk on behalf of some program activity that CHKDSK is
examining at the same time. To verify a volume correctly, the volume
must be in a static state, and the only way to guarantee that state is
to lock the volume. CHKDSK only locks the volume when /F or /R (which
implies "F") is specified. Thus, you may need to run CHKDSK more than
once to get it to complete all stages in read-only mode.
If you are running chkdsk from a command prompt, you are not in the
static state required and you may see errors "when no real corruption
is present". This is why it works okay in RC and when you reboot.
In simple terms that means that whilst chkdsk is running in read only mode which does not require the hard drive to be locked, as it is when you receive the message chkdsk cannot be run as the volume is in use. So it is entirely possible that whilst chkdsk is trying check the file structure, the files are being written to. hence chkdsk reports errors.
There are basically and this is only a simple explanation:-
1. File errors - caused by many things, including shutting down when the drive is being written to - for example updates are being installed. - repairable, even if it is so severe that it requires a reinstallation.
2. Failing sectors of the drive.
For this purpose, although it is not actually as simple as this :-
The physical HDD is divided into sectors, which is the smallest unit of storage possible. The sector-size is defined during the low-level format performed by the HDD-manufacture (Standard 512 Bytes).
When formatting a HDD-partition it is divided into clusters with a certain cluster-size. A cluster is a group of sectors and can can only be occupied by one file, so if having a
10 KByte file and a 4 KByte cluster-size, the file would occupy 3 clusters and 12 KByte space. This would create a so called "slack" of 2 KByte.
These bad sectors cannot be repaired, if they are REALLY bad, in otherwords tiny portions of the drive that are no longer capable of retaining data.
When you read that the bad sectors have been repaired, if they were actually failing sectors, they can NEVER be repaired. Chkdsk retrives your data from the failing sector and rewrites it to good sectors.
That failed sector is then marked as BAD and data is not then wtitten to it in the future.
3. Mechanical errors
On all hard drives, except for the Solid State drives, there are mechanical parts consisting of course not only of the disc itself but a read/write head, which moves across the platters of the disc, so close to it that we are talking about very fine measurments. If the disc is subjected to shock, especially whilst it is running resulting in "damage" for the sake of simplicity of explanation then the drive is useful ONLY as a paperweight. (Unless of course your data is so valuable that the cost of retrieval is irrelevant|)
That in simple terms aside from the very unusual failure of the electrical components of the drive - is more or less it.
4. Did you burn the CD as an ISO image if not it will not work.
100% correct - complete waste of time.
Finally; the hard drive is pretty old now, and I imagine them micro- particles will probably have drifted, or whatever, and it's true that the old PC was shut down improperly MANY times (not by me!). Do you think I should just buy a new one? I'd rather that, than to have a defective one
With the amount of money you are spending - IF presumably you get the position - and are then able to commence your build - putting that hard drive in, is a waste of time.
Good luck with the interview.
I suggest you post when you have the parts if you require any further advice, we will be more than willing to assist.
OR of course, if you have any last minute questions before purchase.