Formatting a hard drive wipes all data on the drive by overwriting the existing data with zeros or random data. Formatting is often done for several reasons:
- To erase all data and start with a clean drive
- To change the file system of the drive (e.g. FAT32 to NTFS)
- To resolve filesystem errors or corruption
- To partition or repartition the drive
- To remove viruses and malware
Formatting completely erases all files, applications, operating systems, and other data stored on a hard drive. It creates a blank slate so a drive can be reused or repurposed. However, many wonder if formatted data can ever be recovered.
Can Data Be Recovered After Formatting?
Just because a drive has been formatted does not mean the data is gone forever. Formatting simply changes how the files are organized and referenced on the hard disk – it does not actually remove or erase them . The files and folders are still physically present on the drive, but the “signposts” leading to them have been deleted. The data remains intact until it is gradually overwritten by new files in the future.
Therefore, with the right data recovery tools and techniques, it is often possible to “unformat” a drive and regain access to the files. The earlier action is taken after formatting, the better the chances of recovery. But even months or years later, specialized recovery software can dig deep to find remnants of old files and reconstruct them.
How Formatting Works
When you format a hard drive, the file system information and structure is erased and recreated, but the actual data on the drive is not immediately deleted. Formatting overwrites the index of where files are located on the drive, but generally does not overwrite the actual files themselves (source: https://www.reddit.com/r/datarecovery/comments/p4ms0n/external_hard_drive_formatted_for_ps5_now_want_my/).
The formatting process removes the file system and partitions, then creates new empty ones on the drive. The data from the old file system still remains on the drive until it is overwritten by new data. So formatting does not immediately destroy or delete data, it just removes the “roadmap” to where the data is stored (source: https://www.fonedog.com/data-recovery/initialize-disk.html).
This allows recovery software to scan the raw data on the drive and rebuild the file structure so the old files can be retrieved. As long as the old data sectors have not been overwritten by new data, formatting alone does not make data unrecoverable.
Data Recovery Software
There are many data recovery software options available to attempt restoring data after a format. Some popular free data recovery software programs include:
- Recuva – This free Windows data recovery tool developed by Piriform can recover files deleted from your Windows computer, recycle bin, memory cards, and external hard drives. Recuva has a reputation for being easy to use. Source
- TestDisk – This free, open source data recovery utility can recover lost partitions and make non-booting disks bootable again. It works for Windows, Mac OSX, and Linux. Source
- PhotoRec – This free, open source file recovery software is designed to recover lost media files like photos, videos, documents, and archives from formatted or damaged devices. It works for Windows, Mac, and Linux. Source
Some of the top paid data recovery software options include:
- Stellar Data Recovery – This data recovery tool works for Windows, Mac, iOS, and Android to recover lost or deleted files from hard drives, RAID arrays, SSDs, and more. Stellar is known for its deep scan capabilities. Source
- R-Studio – This advanced data recovery software supports recovery even if a disk is damaged or has lost its partition info. It can reconstruct RAID arrays and works for Windows and Mac. Source
DIY Data Recovery
For those not ready to pay for professional data recovery services, there are several free software options you can attempt to recover files yourself after a hard drive format including: Disk Drill, Recuva, PhotoRec, and EaseUS Data Recovery Wizard. These tools scan your hard drive and attempt to recover files that still exist despite the format procedure. Many of these tools like Recuva and Disk Drill have user-friendly interfaces that make the recovery process straightforward even for novices.
The main benefit of DIY recovery is that it is free, so it costs you nothing to at least attempt getting your files back. However, success rates tend to be lower than professional services. The free scanning tools may miss damaged or complex file types. You also have to be extremely careful in how you handle the drive during scanning and recovery, as any further writes or damage could overwrite your files permanently.
Overall, DIY recovery with free tools works best for simple accidental formatting cases without physical damage to the drive. But for more complex recovery cases like formatted RAID arrays or drives with mechanical issues, it is smarter to use professional recovery right away for the highest chance of success.
Professional Data Recovery
For critical or complex data recovery cases, professional data recovery services are recommended. These services have access to advanced tools, cleanroom facilities, and years of specialized expertise to recover data from failed drives.
Professional data recovery labs open the drive in a dust-free cleanroom to prevent further contamination. They utilize specialized equipment like platter transplants and read/write head transplants to extract data from the drive’s platters even when the drive cannot power on.
For logical recoveries, they use advanced data recovery software and techniques like rebuilding the file system to make the data readable again. Some providers like Magnext Data Recovery offer encrypted transport of recovered data for security.
Professional data recovery services typically charge $300 to $2000+ depending on the drive type, failure, and desired turnaround time. The costs reflect the sophisticated techniques, cleanroom facilities, and labor required for professional-grade recovery.
While expensive, professional recovery offers the highest chance of success for invaluable or irreplaceable data from a failed drive. For businesses or critical personal data, the high costs can be worthwhile to restore access to important files.
Data Recovery Success Rates
The success rate for data recovery after a drive has been formatted can vary greatly depending on the circumstances. According to UFS Explorer, recovery chances are higher when a drive is formatted with the same file system – for example, NTFS overwritten with NTFS. Recovery chances decrease significantly when a different file system is used to overwrite the original one (source).
In general, data recovery companies report success rates of 80-95% for recovering data after formatting, but this depends heavily on the complexity of the recovery (source). Some basic ways to measure success rates are comparing the amount of data recovered versus the estimated amount that existed originally. The more fragmentation and overwriting that occurs after formatting, the lower the chances of recovery.
For DIY recoveries, success rates also depend on using the proper data recovery software and techniques. Overall, the best chances of recovering data after formatting involve using professional services quickly before too much new data is written.
There are some best practices you can follow to help prevent needing data recovery after formatting a hard drive:
- Back up your data regularly – Make copies of important files and folders on a separate drive or cloud storage. This way you’ll have copies if you accidentally format the wrong drive.
- Be careful when formatting – Double check you are formatting the correct drive before proceeding. Accidentally formatting the wrong drive is a common mistake.
- Use file recovery software – Install a file recovery program like Recuva ahead of time. This will allow you to attempt recovering deleted files immediately after a mistake.
- Store less sensitive data on the drive – Don’t use your primary hard drive to store highly sensitive or irreplaceable data. Use an external or backup drive for this purpose.
- Reformat using simple “Quick Format” – If reformatting a drive, use the quick format option. This preserves more data and requires less overwriting.
- Write protect important partitions – Use partition management software to write protect partitions you want to prevent accidentally formatting.
Following these tips will help avoid disasters that require data recovery after formatting a drive. Prevention is the best solution.
When Data Is Unrecoverable
In some cases, formatting a hard drive will make the data permanently unrecoverable. According to Secure Data Recovery, if a full format or “zero-fill” format was performed, it overwrites the existing data to make it irretrievable. This is because the format fills the drive with zeros or random bits of data, removing any trace of the original files.
Similarly, Super User explains that a full format on Linux immediately makes data unrecoverable by writing over all sectors of the hard drive. The more times a full format is run, the less likely data can be recovered.
Formatting and then continuing to use the hard drive, saving new files to it, will also reduce the chances of recovering the original data. The saved data overwrites deleted file segments over time.
In short, if a full format was done, especially multiple times, and the drive continues to be used, the prior data is likely unrecoverable through any means.
In summary, while formatting a hard drive does not completely erase its data, recovering lost files after formatting is still challenging. The success of DIY data recovery depends on various factors like when the drive was formatted, if new data has overwritten the old files, and the recovery method used. For best results, stop using the formatted drive immediately and seek professional help as soon as possible.
That said, regularly backing up your data remains the most reliable way to avoid losing important files. If you do accidentally format a drive, act quickly and use data recovery software or services for the best chance of restoring your files. Avoid further saving or installing anything on the formatted drive until recovery is complete. With the right tools and precautions, you may be able to successfully recover data after formatting a hard drive.