Partial RAR extraction using WinRAR

WinRAR allows users to split file archives into smaller pieces (a feature present in most major archiving software these days). It is sometimes the case that one or more of these pieces are missing, and as such the archive cannot be completely reassembled. This tutorial shows how to partially recover files from a RAR that does not have all pieces present.

Introduction

This tutorial assumes you are running either Windows 2000/XP and have a copy of WinRAR installed (Download WinRAR: http://www.rarlab.com/download.htm). This tutorial works best for RAR files that contain video media.

There are a number of caveats associated with this method (e.g. extraction of text files or images is unlikely because the packaging software will have probably compressed it); please read the list before continuing. With this in mind, let’s get started…

Background

Archive files that have been split are often suffixed .001, .r01 or simply .part01 (where the final digits represent which piece of the overall archive it is, i.e. a 5 part archive might have files with .001, .002, .003, .004 and .005 as suffixes). WinRAR extracts and assembles files in the Windows temporary folder, we will exploit this mechanism to extract files from archives where we do not have all of the pieces.

The method in the madness!

  1. Double click one of the archive files (or open it manually from within WinRAR).
  2. Tell the program to extract the file somewhere on your computer.
  3. An error message will pop-up and inform you that not all pieces were present to complete the extraction.

    A screen shot of the window in WinRAR

    DO NOT CLOSE THIS WINDOW!!!

  4. Navigate to the temporary directory for your username. The default on Windows XP is:
    C:Documents and SettingsYOUR USERNAMELocal SettingsTemp.
  5. This folder/directory is usually pretty full. Look for a directory called Rar$****.*** (where the *s represent any character). The naming convention might be different between versions, if you are having trouble finding this directory, try searching the temporary directory for file that you are trying to extract (CTRL+F and then the file name).
  6. Once you’ve located the file, copy it to your desktop or another ‘safe’ directory (i.e. outside of your temporary folder).
  7. The file you’ve extracted should be the combined contents of the archive pieces you have available at the time of extraction.

Caveats

There are several caveats to this method, please read these before trying the above or you might find yourself wasting a lot of time!

  1. Text and image files are almost always compressed, the output will be completely useless without all the parts since WinRAR seems to perform the decompression step last!
  2. This method cannot be used to extract password protected files if you do not know the password.
  3. The data will only be extracted up to the last sequential piece, e.g. if you have pieces 1, 2, 3, 6 and 7 of a 10 piece archive – the extraction will halt after extracting from piece 3.

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