What does it mean for a file to be overwritten?
When a file is overwritten, the existing data in the file is replaced with new data. Technically this means the bits representing the file’s contents are replaced with new bits (Webopedia).
On storage media like a USB drive, each file is stored in a particular physical location. When that location is written to again, the original 1’s and 0’s representing the old file’s data are replaced with new 1’s and 0’s representing the new data. The old data is erased in that physical location (Minitool).
So overwriting a file involves replacing the file’s contents by writing new data to the same storage location. The original data is erased and no longer accessible through normal means. Only the newly written data can be accessed in that location.
Why do files get overwritten on a USB drive?
There are two main reasons files may become overwritten on a USB drive:
Accidental saving over existing files
One of the most common ways files get overwritten is by accidentally saving new files over existing ones. This can happen if you insert a USB drive that already contains files into your computer and save new files to it without realizing you’re overwriting the original data. For example, if your USB drive has your resume on it and you insert it to save a new document without checking the contents first, your new file may overwrite your existing resume.
To avoid this, always verify the contents of a USB drive before saving new data to it. Additionally, use descriptive filenames and folder structures so you can easily identify existing files.
Corruption/damage to the USB
If a USB drive becomes corrupted or damaged, its file system can become unstable. This may result in new data overwriting existing files. For example, if there is a bad sector on the drive, the computer may write a new file over top of the corrupted data in that sector. Electrical issues, accidental removal of the drive during writes, malware, and excessive heat can all potentially damage a USB drive and lead to overwritten files.
To minimize this risk, safely eject USB drives before removing them, keep backups of important data, and check drives occasionally for errors using built-in utilities.
In summary, accidental saving and drive errors are the main causes of file overwriting on USB drives. Being cautious and maintaining backups can help avoid losing important data.
Can overwritten files be recovered?
Yes, with the right recovery software it is possible to recover overwritten files, especially if only part of the original file was overwritten (source: https://www.pandorarecovery.com/blog/recover-overwritten-files/). The likelihood of recovering an overwritten file depends on how much of the original data has been overwritten – the less data overwritten, the greater the chance of recovery. Even if sections of the original file were overwritten, recovery software can piece together the remaining fragments to restore the file. However, if the entire file has been completely overwritten, recovery becomes much more difficult.
This is because when a file is overwritten, the original data is not immediately erased. Instead, the file system simply marks the space occupied by the original file as available for new data. Until that space is filled by new data, recovery is possible by scanning the raw data on the disk. Recovery software looks for file signatures and metadata to identify remaining fragments of the original, overwritten file.
Therefore, the key is to stop using the USB drive as soon as possible after overwriting, and quickly run file recovery software before the original data clusters are entirely overwritten with new data (source: https://nordic-backup.com/blog/how-to-recover-overwritten-files-quickly/). The chances of full recovery decline the longer you continue using the USB drive normally.
Factors that affect recoverability
There are several key factors that determine whether an overwritten file can be recovered:
The amount of the old data that was overwritten – The more data from the original file that remains intact and was not overwritten, the higher the chances of recovering that file. If the entire file was overwritten, recovery becomes very difficult.
The file type – Text files and other file formats with simple structures are easier to recover compared to complex file types like photographs or videos. The reason is that even small portions of recovered text may contain meaningful information, while recovering partial multimedia files may not be useful.
The software used – Specialized data recovery software like PitsDataRecovery use advanced techniques to read and reconstruct partially overwritten data. The capabilities of the software play a key role in determining what can be recovered.
In addition, the storage medium, the OS file system, and whether encryption was used also impact recoverability. Generally, the more layers of abstraction between the raw storage and the files, the harder recovery becomes once data is overwritten.
Best Software to Recover Overwritten Files on USB
The top software programs recommended for recovering overwritten files on a USB drive are:
Stellar Data Recovery – This is a paid software with a free trial available. It has advanced scanning capabilities to find overwritten and lost files. Stellar can recover from formatted drives as well.
EaseUS Data Recovery – Another paid software with a free trial. EaseUS offers different pricing tiers based on features needed. It can recover from overwritten, deleted, corrupted, and lost files.
There are also free open source options like PhotoRec and R-Studio. However, the paid software tend to be easier to use and offer better recovery capabilities for overwritten files.
The premium software is recommended if overwritten files are critical. They invest more into advanced scanning technology and support to recover files other free software cannot. The free trials allow testing recovery before purchasing.
Step-by-step recovery instructions
To recover overwritten files on a USB drive, we recommend using recovery software like EaseUS Data Recovery Wizard (Freeware) or MiniTool Power Data Recovery. These programs can help you restore deleted and overwritten files in just a few steps:
1. Connect your USB drive to your computer and launch the data recovery software. Make sure to use a computer that the USB drive was previously connected to, as the software scans that computer’s drive for file remnants.
2. Select the USB drive to scan. The software will start scanning the drive for recoverable files.
3. Once the scan completes, preview the files found. The software will display files it found that were deleted and overwritten. You can preview image, video, document, and audio files.
4. Select the overwritten files you want to recover and restore them. Pick a folder on your computer or external drive to save the recovered files to.
5. The software will recover and restore the overwritten files to the selected location. Make sure to save them to a different drive than the USB they were deleted from.
This process can recover deleted files like documents, spreadsheets, photos, music files, videos, and more. The software scans the USB drive and finds remnants of overwritten files to restore. Just be sure to use the USB drive with the computer you are recovering with.
Source: https://www.minitool.com/data-recovery/recover-overwritten-replaced-files-free.html
Recovery limitations
While data recovery software can often retrieve overwritten files, there are some risks and limitations to the process. Overwritten files are not always fully recoverable, especially if they have been overwritten multiple times. This is because each time new data is written over a file, more of the original data is destroyed or corrupted beyond repair.
According to Challenges in Recovering Overwritten Data | by Scot Comp, once a file has been overwritten, it becomes impossible to recover the previous version. However, data recovery software attempts to retrieve fragments of the original data that may still exist. The more times a file is overwritten, the less likely it is anything can be recovered.
There are also risks associated with data recovery. If the recovery software is not used properly, it could cause further data loss or corruption. Attempting to recover overwritten files may also negatively impact the storage device if there are sectors that are physically damaged. The recovery process could worsen the damage. In some cases, the device may fail completely during recovery.
Users should be aware that while overwritten files can sometimes be retrieved, there is no guarantee. The likelihood of recovering the complete original file diminishes with each overwrite. There are also inherent risks that could lead to irreparable data loss. Care should be taken when attempting overwritten file recovery.
Tips to Avoid Overwriting Files on a USB Drive
Here are some tips to help avoid accidentally overwriting files on your USB drive:
Safely eject the USB drive before removing it. On Windows, click the “Safely Remove Hardware” icon in the system tray and select your drive. On Mac, right-click the USB drive icon on your desktop and select “Eject”. This ensures any writes to the drive are completed before you unplug it.
Create backups of important files. Copy important files from your USB drive to another storage location like an external hard drive or cloud storage. This provides a backup in case files get overwritten on the USB drive.
Consider setting the drive to read-only if you want to prevent any changes. On Windows, right-click the drive, select Properties > General > Attributes and check “Read-only”. On Mac, click the drive icon and select File > Get Info. Check “Locked” to make the disk read-only.
Use write protection tabs if available. Some USB drives have a physical switch or tab to toggle write protection on and off. Slide the tab to the lock position to prevent writing.
Be careful when copying files to the drive. Accidentally pasting or dragging files onto the USB drive can overwrite existing files. Always verify the destination location before transferring files.
Eject and re-insert the USB drive after large file transfers. This clears any cached writes and ensures all data is actually written to the drive before removing it.
When to Use a Data Recovery Service
For many overwritten files, using backup software or utility programs may be sufficient to recover previous versions. However, for extremely valuable or irreplaceable files, it can be worth hiring a professional data recovery service.
Data recovery experts have specialized tools and techniques that may be able to rescue files even in complex situations where DIY solutions fail. This is especially true for mechanical failures or severe overwriting. The more overwritten a file is, the harder it is to recover previous versions.
Examples of valuable files that may warrant professional recovery include:
- Files related to your business, such as accounting data or intellectual property
- Personal files like photos or videos of major life events
- Critical system files that render a computer unbootable
Recovering these types of files is worth the high cost that data recovery services often charge. Prices can easily run $500 or more for personal files and much higher for business clients. But for truly irreplaceable data, the expense can be justified if it means restoring lost files.
Just be sure to choose a reputable service with strong security practices, and be aware that even experts cannot guarantee recovery. But if DIY solutions all fail, a professional recovery service may be your best chance at restoring overwritten files.
FAQs
Here are some commonly asked questions about recovering overwritten files from a USB drive:
Why can’t I see my overwritten files in the USB drive?
When a file is overwritten on a USB drive, the original data is erased from the drive’s file table. This makes the original file seem to vanish from the USB drive. However, until new data fully overwrites all the sectors occupied by the original file, recovery is possible.[1]
Can I recover an overwritten file if I don’t have a backup?
Yes, it’s often possible to recover overwritten files even without a backup. As long as the original data hasn’t been completely overwritten, data recovery software can scan the USB drive and rebuild the file.[2]
Why does the recovered file seem corrupted?
If an overwritten file was only partially overwritten before recovery, the recovered file may be corrupted or incomplete. The more the original data is overwritten, the less likely a complete recovery becomes. Recovering sooner improves the chances.[3]
Can I recover overwritten files after reformatting the USB drive?
If you reformat the USB drive after files were overwritten, this makes recovery much more difficult. Reformatting clears the drive’s file table entirely. However, recovery specialists may still attempt to scan the drive’s sectors to rebuild overwritten files.[3]