Data Protection and Recovery Techniques Part 5: Recovering a File to Another Drive with Norton Disk Editor
Data Protection and Recovery Techniques Part 5: Recovering a File to Another Drive with Norton Disk Editor
Introduction
In Part 4 of this series, I described the process of undeleting a file using Norton Disk Editor. As you can see from reviewing this article, Data Protection and Recovery Techniques Part 4: Using Norton Disk Editor, the process of undeleting a file to the same drive requires quite a few steps that, if not done correctly, could cause problems for your system. That is why I recommended using a floppy disk the first few times you perform this task as I did in that article.
What should you do if you need to retrieve an erased file from the hard disk? Its safer to write the retrieved file to another disk or media, such as a floppy disk (if the file is small enough), a writeable CD or DVD, flash media such as a CompactFlash or USB flash drive, another hard drive, or a different partition on the same drive. You can also perform this task with Disk Editor.
Preparing to Recover the Lost File
Before you start Disk Editor, run CHKDSK to determine the cluster (allocation unit) size of the drive. In this example, the drive is using the FAT32 file system and has a cluster size of 4,096 bytes. To determine the number of clusters the file uses, divide the file size by the cluster size, and round up to the next integer value. For example, if you had a file that was 4100 bytes and the cluster size was 4096 bytes:
4100 / 4096 = 1.000976563 = 2
Since the division of the file size by the cluster size is larger than 1, but smaller than 2, it would be rounded up to 2, meaning this file would use 2 clusters on the drive.
After starting Disk Editor, select the erased file (see Figure 1) to see the size of the file. The file Im retrieving is 17,408 bytes. 17408 divided by 4096 equals 4.25; since a file must use an entire cluster, we round 4.25 up to 5; the file uses five clusters. To display its cluster chain, press Ctrl-T.
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Figure 1 |
Viewing an erased file in Norton Disk Editor.
In this case, the cluster chain has empty spaces starting at cluster 75,207 ranging through 75,268. Its obvious that not all of these clusters belong to this file, but probably the first five do. Since I am trying to retrieve the data to another drive, I need to view the clusters listed to see if they contain the data for which I am looking.
Locating the Data from the Lost File
To view the data stored in the cluster range, open the Object menu, select Cluster, and enter the range. In this case, that range is 75206 through 75220 (see Figure 2).
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Figure 2 |
Selecting a range of clusters to view in Norton Disk Editor.
As expected, cluster 75207 is the beginning of a Microsoft Word file. To view the file contents more easily, I can press F3 to switch to Text View. As I scroll down through the file, I can see that the data stored in clusters 75207 through 75211 are definitely part of the same Microsoft Word file. I can also see fragments of junk text apparently left over from files that had previously occupied this space. To determine where the file actually ends, press F2 to switch to Hex view. In this view, I can see several rows of 00. These indicate the end of the file. However, while junk data is present in the cluster, it doesn't start in the sector until after the end of the document (see Figure 3).
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Figure 3 |
Scrolling through an erased file with Disk Editor.
1. Start of file
2. End of file
3. Junk data in cluster after end of file
Switching to Viewing the Data by Sectors
To copy the contents of these clusters to a file safely, its best to specify the sectors which contain the file. When I return to the top of the cluster range, I see that cluster 75207 is also sector 608470. When I scroll down to the end of the document, I see that the end of the document is located in sector 608503. I can write this range of sectors to a new file and retrieve my document.
Copying the Sectors to Another Drive
To write these sectors to a new file, I get a blank, formatted floppy disk and insert it into drive A: Next, I open the Object menu and select Sector. I specify 608470 as the starting sector, 608503 as the ending sector, and then click OK (see Figure 4). I scroll through these sectors one more time to confirm that these sectors contain my document.
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Figure 4 |
Specifying a sector range to check for lost data.
When Im satisfied that these sectors contain my document, I open the Tools menu, click Write Object To (Alt-W), select To a File, select drive A: and specify a filename (dont use a long filename; use no more than eight characters plus three-letter extension, such as LOSTDOC.DOC). Click OK to write the file to the floppy disk (see Figure 5), then Yes to confirm. A status bar appears as the sectors are copied to the file.
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Figure 5 |
Copying specified sectors to a file with Disk Editor.
To verify that the file is working, I close Disk Editor (Alt-O, Exit), move the floppy disk to a computer with Microsoft Word or a compatible word processor installed, and open the file. Because I copied only the sectors that contain data to the disk, the file is in perfect condition (see Figure 6).
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Figure 6 |
Opening the recovered file with Microsoft Word.
Conclusion
If you followed this procedure, I'm sure you realize that the more contiguous (using consecutive clusters) the file is, the easier it will be to recover. In fact fragmented files can be very difficult to recover, the more fragmented the more difficult it will be. For this reason, I highly recommend you defragment your drive on a regular basis, normally right after doing a backup. You can use the Disk Defragmenter program included with Windows, but that program is slow and unreliable (often seems to stop and hang if you don't run it in safe mode). Better yet, I recommend using the Speed Disk program that comes with the Norton Utilities (which you already have if you have the Norton Disk Editor), or the super-fast Vopt utility from Golden Bow http://www.vopt.com.
As you have learned from Parts 4 and 5 of this series, Norton Disk Editor is a powerful tool you can use to explore drives and retrieve lost data. However, as other parts of this series have shown, your best data recovery technique is to avoid the need for data recovery. Think before you delete files or format a drive, and make backups of important files, and you wont need to recover lost data very often.
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