# Corrupt 7z file



## slumber94 (May 4, 2016)

Hi.

Before I reinstalled Windows 10, I decided to make a pretty big backup of my files, which resulted in a 11gb~ archive full of different files (images, songs etc). I archived it with 7z, and transfered it onto my external hard drive, which is not at fault here. Thing is, whenever I try to open it (with both winrar and 7z), I get this:








I tried editing the first two lines with a hex editor (solution which I found on the 7z site faq) but to no avail. I am really desperate to recover the files in this archive, it contains a lot of personal work.

Thanks to everyone who reads this thread.​


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## Corday (Mar 3, 2010)

How to recover corrupted 7z archive


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## slumber94 (May 4, 2016)

Did anyone ever fix a corrupt archive using that tutorial?


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## Corday (Mar 3, 2010)

Thought you might find which of the solutions fixes what you did. It's possible that the compressed file, decompressed at the transfer to the external, then recompressed which could be where the trouble began. The actual path designation might also come into play.


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## slumber94 (May 4, 2016)

Corday said:


> Thought you might find which of the solutions fixes what you did. It's possible that the compressed file, decompressed at the transfer to the external, then recompressed which could be where the trouble began. The actual path designation might also come into play.


I get what the tutorial is trying to say, but am I supposed to edit the hex values like in that example? Or is that only for example's sake? I just don't get it, sorry, I have no experience with this type of programs.
As for the path designation, are you implying that during the reformatting of the hard drive the partition letters changed and made the archive unrecognizable? It wouldn't be the first time I run into this issue, sometimes when I connect my external hard drive, the OS assigns it a different letter and all programs dependent on said external hdd won't function anymore.

tl;dr Can anyone help explain how to repair the hex values? I just don't get it...


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## btufty (May 1, 2016)

anything is worth a try and possibly an extraction might help. a free program like FTK can dig into most files and drives
FTK Imager version 3.4.2 (for use with version 6 products and newer) | AccessData


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## slumber94 (May 4, 2016)




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## slumber94 (May 4, 2016)

This is what I see when I open the archive with a hex editor. I tried the solutions on the 7z faq by replacing the values with those in the example. Can anyone good on this topic provide support? I really am desperate to recover the data in this archive..


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## Corday (Mar 3, 2010)

Hope someone can be of further assistance, but before going on, why did you *reinstall *Windows 10 originally?


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## slumber94 (May 4, 2016)

Corday said:


> Hope someone can be of further assistance, but before going on, why did you *reinstall *Windows 10 originally?


Because I upgraded my cpu and ram and a friend advised me to get a clean reinstall claiming that it would fix my bsod issues (explained in another thread).


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## Corday (Mar 3, 2010)

The reason I asked is I was thinking whatever was wrong caused the file corruption.


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## slumber94 (May 4, 2016)

Corday said:


> The reason I asked is I was thinking whatever was wrong caused the file corruption.


Highly doubtful that it was damaged in any way during the archiving process. I waited almost an hour for it to compress, and I just can't figure why does it have this error, I have never encountered this type of error so far.


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## Corday (Mar 3, 2010)

Grasping at a few straws here:
1. Looked at your BSOD post and was wondering if hardware problem could have caused corruption (faulty bus?)
2. External not powered through UPS so a surge would cause the problem
There are recovery services out there, but they're expensive.


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## slumber94 (May 4, 2016)

Corday said:


> Grasping at a few straws here:
> 1. Looked at your BSOD post and was wondering if hardware problem could have caused corruption (faulty bus?)
> 2. External not powered through UPS so a surge would cause the problem
> There are recovery services out there, but they're expensive.


It just seems so unlikely that hardware influenced the basic process of archiving... all the disks are fine, ran disk checks and /scannow and nothing came up. Please, someone take a look at that hex screenshot and tell me exactly what to do...


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## Corday (Mar 3, 2010)

I'll see if anyone on staff is a base 16 expert.


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## slumber94 (May 4, 2016)

Corday said:


> I'll see if anyone on staff is a base 16 expert.


Thanks for your kindness. I need to recover this archive by all means, most of my university work is there...


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## spunk.funk (May 13, 2010)

Post a screenshot of the _edited _archive in a hex editor and compare it to your previous one and the one in the recover 7z link.


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## slumber94 (May 4, 2016)

spunk.funk said:


> Post a screenshot of the _edited _archive in a hex editor and compare it to your previous one and the one in the recover 7z link.


I might be dense over here, but what do you mean edited? All I edited was after the examples shown on the 7z faq... don't see the point, I really don't get what you're saying :ermm:


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## spunk.funk (May 13, 2010)

> All I edited was after the examples shown


 If you changed (edited) the header as outlined in the link, compare the headers in your unedited version, with the version that you edited, and the example in the link. Make sure your Edit matches the example in the link. If you need help, post a screenshot of your edited header so we can compare it.


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## slumber94 (May 4, 2016)

This is how the start header looks like after editing (you can compare to the ss I posted above), however I do not know what to do to the *End Header*


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## spunk.funk (May 13, 2010)

In the link in post #2 go to* Recover Archive*, and follow those instructions for copying contents if there is no End Header showing.


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## slumber94 (May 4, 2016)

And this supposedly is the End header which looks nothing like in the example. I'm very confused over here.


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## slumber94 (May 4, 2016)

spunk.funk said:


> In the link in post #2 go to* Recover Archive*, and follow those instructions for copying contents if there is no End Header showing.


I am going insane :banghead:.


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## slumber94 (May 4, 2016)

slumber94 said:


> I am going insane :banghead:.


When I replace the header with these values: "
0000000000: 37 7A BC AF 27 1C 00 04 00 00 00 00 00 00 00 00 0000000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00"

it gives this message: "Can not open the file as [7z] archive
Is not archive"

help...


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## spunk.funk (May 13, 2010)

Open a new blank Archive in the Hex Editor, and follow the instructions in the link and copy the contents in the troubled Archive between the Top and the Bottom Header, deleting the data in the blank Archive and just leaving the Headers, then copy the data to this archive that you are trying to restore.


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## slumber94 (May 4, 2016)

spunk.funk said:


> Open a new blank Archive in the Hex Editor, and follow the instructions in the link and copy the contents in the troubled Archive between the Top and the Bottom Header, deleting the data in the blank Archive and just leaving the Headers, then copy the data to this archive that you are trying to restore.


...blank archive?


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## slumber94 (May 4, 2016)

The problem seems to be on my part. I sent another archive I made to a friend and asked him to see if he can open it, and after he applied the headers fix mentioned in the 7z faq, he could see the list of files and could even extract. I still haven't tried with the big archive, I have yet to send it to him, but when I will do so I will post the results here for closure.
While I should be able to recover the files, it still baffles me what actually went wrong, and don't think I will ever find out..


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## spunk.funk (May 13, 2010)

The headers became corrupted, reediting them in the Hex Editor will fix the problem.


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## slumber94 (May 4, 2016)

spunk.funk said:


> The headers became corrupted, reediting them in the Hex Editor will fix the problem.


No, it still doesn't work.


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