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For example, I have Windows 7 on a hard drive where SMART reports "many bad sectors". If I buy a new hard drive, and attempt to clone over Windows to the new hard drive, will that fix the problem so I have Windows on a clean hard drive, or will that also copy over the bad sectors and so therefore SMART will find errors on the new hard drive?

My guess is that bad sectors aren't propagated during a clone process, but I could be wrong, so I wanted your opinion. THanks!

EDIT: Actually, I copied windows to a new hard drive, and the new hard drive has the bad sectors. So my question is a bit backwards, but you get the idea. :)

Based on the answers: cloning from a clean drive to a bad-sector drive is fine, data-wise. From a bad-sector drive to a clean drive is also fine. And, the cloning process itself won't destroy any data. The only thing to worry about is if data was lost when the original drive acquired bad sectors.

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if it's the case that the physical problems affect the clone, the 1s and 0s.. then maybe chkdsk on the new drive afterwards, will pick up errors and fix them, and then if those things are true, then for sure it'll be a permanent fix.. until the new drive gets physical errors. but I don't know if those things are ever the case. – barlop Apr 20 '11 at 23:30
I think SMART only shows physical issues, data about the drive given by the drive, not from scanning user data on the drive. (I assume that's how it works hence how SMART data is given so fast). So i'm sure it wouldn't show issues but the (user) data on the drive may have issues I don't know. At worst it shouldn't be too bad. – barlop Apr 20 '11 at 23:33
up vote 4 down vote accepted

The actual bad sectors are a property of the physical material in the drive, and are not copied. In other words, if you have ten bad sectors on hard drive A, and five on B, and you clone A onto B, B still has exactly the same five bad sectors that it did before the cloning process.

I would assume that the hard drive itself (or any checkdisk-style process run on the drive) will map those sectors elsewhere so that the cloning software doesn't try to write data to them, but that has no impact on the actual bad sectors present on the drive, and doesn't change the answer to your question.

You do have one problem, however. If the hard drive you're trying to clone has lots of bad sectors on it, then data may have already been lost. So you're probably better off reinstalling anyway, and moving your data over afterward.

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Thanks for the answer! The cloned Windows 7 works perfectly (from what I can tell) and is on hard drive B (the destination drive after cloning and which has the bad sectors), so I'm guessing that the copied data is fine if there were no errors on hard drive A. Thanks! That means I have no worries as to data loss! I just need to make a back up. :D – trusktr Apr 22 '11 at 5:35

Copying means reading from the source and writing to the destination. Bad sectors can not be read, so there is nothing to write to the destination. Most copy utilities will fill in all zeros for sectors they can not read.

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Can filling in with all zeros potentially change the contents of so as to make it un-useable? – trusktr Apr 22 '11 at 5:32
@Joe Pea no, all zeros is a perfectly valid set of data to write and read back. – psusi Apr 25 '11 at 13:28

Bad sectors are not transferred during the cloning process. So SMART will not see the bad sectors from the old drive appearing on the new drive.

One problem you may have is file damage depending on how many unreadable bad sectors you have. You may see some damaged files that have missing data or "holes" in them. There are advanced cloning methods that can identify which files are damaged due to bad sectors.

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Thanks. Please see my update above! – trusktr Apr 22 '11 at 5:33
« There are advanced cloning methods that can identify which files are damaged due to bad sectors. » Could you be more specific ? – Gabriel Jul 26 '11 at 18:04

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