Get back Excel file...
 
Notifications
Clear all

Get back Excel files after D drive

3 Posts
3 Users
0 Likes
352 Views
tracedf
(@tracedf)
Posts: 169
Estimable Member
 

You may be out of luck. When you reformatted, you replaced the file table that tracks each file on your drive. Recovery tools operate by scanning every sector on the drive in an attempt to locate files and put them back together. This generally requires a recognizable header, a file that is stored in one continuous piece and (ideally) a recognizable footer. Excel has a recognizable header/footer so if your original file is five blocks of data stored in one piece, it might look like this

[Header|Data1] [Data2] [Data3] [Data4] [Data5|Trailer]

Most data recovery tools will be able to handle this. If the file is broken up or stored out of order, most/all tools will be unable to recover the file. Fragmentation is common so your Excel file could be stored with other data/files and unused blocks between the blocks that make up your file

[Header|Data1] [Data2] [Garbage] … [JPG Header] [JPG Data] … [Data3] [Data4] [Data5|Trailer]

Most carving programs won't be able to tell that the blocks in the middle do not belong to your file so they will give you everything from the header to the trailer and you will end up with a corrupt Excel file. In order to carve a file like this correctly, you need to be able to identify which blocks belong to your file and which do not. There has been some work done in this area but, off-hand, I don't know of a tool that does this for Excel or even whether it's possible for Excel.

-tracedf

 
Posted : 06/04/2016 1:46 am
(@mscotgrove)
Posts: 938
Prominent Member
 

Are you talking XLS or XLSX files. The later should be easier as they are basically zip files with a nice structure with small sections (because they are compressed).

I did start a function on my recovery software to recover fragmented ZIP files, but it is still best described as beta level. If there are a few Zip type files it can work, but if there are lots, there is a problem of too many possible matches.

XLS files are harder because they are larger, and not saved sequentially within the file, ie there are two levels of fragmentation, the file and the file system

 
Posted : 06/04/2016 4:24 am
joakims
(@joakims)
Posts: 224
Estimable Member
 

What is the filesystem now, and what was it originally?

 
Posted : 06/04/2016 2:42 pm
Share: