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I cut and paste a huge and important file from a hdd to another. I know it's a mistake. The process took hours, but before completion, explorer crashed (windows 7 at the time), and the progress bar was gone. I would like to know how Windows behave in that case.

Is there a chance of data loss, or is windows 7 smart enough to "close and cancel" the current file ? I have doubts. If data was lost, does the source of the cut and paste matter (from the external hard drive, or from the system hard drive) ? I'm really interested to know how a potential data loss can translate, assuming it crashed while copying a txt file of a few bytes - missing file ? Corrupted file ?

Thank you for any information.

marked as duplicate by Ƭᴇcʜιᴇ007 windows-7 Aug 4 '16 at 14:59

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The easy way of seeing Cut & Paste is to see it as Copy, Paste, Delete.

Avirk explained how it works well in another super user comment:

When you cut and paste the data, the data transfer proceed one by one file from the location to transfer the another location. The files until not complete transferred to another location the file doesn't delete from the original location(from wheres you cut it). If by chance the transfer interrupted the files which has not transferred yet will remain on there original location and you can again proceed your transfer.

There is a very small chance of data loss if the transfer is interrupted due to power failure or a system hang. In my case I never lost data when I cut and paste it from one location to another and never mind what the size it has.

  • I see, so there is no way to know if the crash resulted in lost data ? – Chatai Aug 4 '16 at 13:50
  • If you had a backup to compare with you could compare it, but otherwise it appears not. Its a good idea to copy and paste yourself, then delete after. – Lister Aug 4 '16 at 13:52
  • So it is possible that some entire files (small text files for instance) got deleted after the crash and are lost in a result ? The system is deleting the whole file instead of corrupting it ? – Chatai Aug 4 '16 at 14:23
  • Its possible but you should be safe. As Avirk said, windows copy's the file and after the copy is completed it deletes it. Working on that principle only files which were completely copied should be deleted. I only say you cant be sure because without an original to compare against you cant tell the difference! – Lister Aug 4 '16 at 14:28
  • Since it only deletes After the current file copy is completed a crash will not delete data during a cut-paste. – Moab Aug 4 '16 at 21:24

I would like to know how Windows behave in that case.

It closes and cancels and removes the parts of the file it didn't fulle transfer from target source only if it is a controlled cancellation (e.g. you press cancel, or Windows enforces a cancel for some reason)

A crash is not considered a controlled cancel, but as Lister said, Windows won't delete a file until it is actually (fully) transferred.

On an uncontrolled cancel corrupt/incomplete files may be present on the target destination. The safest way to address it is to simply move the remaining files in the source-storage and tell Windows to REPLACE duplicates.

Note though, that data loss still might have occurred, since the file transfer also has complicated hardware-wise factors that the operating system can't control/monitor in every aspect (such as HDD internal cache etc).

I'm really interested to know how a potential data loss can translate, assuming it crashed while copying a txt file of a few bytes - missing file ? Corrupted file?

It all depends on what kind of file it is and how and what for it is used. As an example: a text file may still be readable, yet some part of it missing. This could be alright, unless this text file is used by some program to read setting or other stuff that might crash the program if incomplete.

You can't really know for sure if there's been any data-loss if you don't have the original set of files to compare total amount of files, exact total size etc.

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