When a file is deleted from your computer, it isn’t actually erased right away. The reference to the file’s location on your hard drive is removed from your operating system, making the file seem to disappear. But the actual data that makes up the file remains on your hard drive until it is overwritten by new data. This provides an opportunity to recover deleted files, if you act quickly and use the right software.
What happens when you delete a file?
When you delete a file, either by hitting delete/backspace or emptying the Recycle Bin, the reference to that file’s location on your hard drive is simply removed. The 1s and 0s that make up the file stay exactly where they are until that space is overwritten by new data. So the file isn’t really gone yet – it just appears that way because the operating system has forgotten where to find it.
This is what allows file recovery software to work. As long as the original 1s and 0s from a deleted file haven’t been overwritten, they can be found again and restored. But it’s a race against time, because any new files saved or programs installed can start overwriting the recoverable data.
Why can’t you recover files after they’ve been overwritten?
When existing files are deleted, all that happens is the references to their locations on the hard drive are removed. The 1s and 0s that make up the actual files stay in place until they get overwritten.
Once another file is written over the same location, those 1s and 0s are replaced with new data. The original file is still there briefly until the new data takes its place. But once full overwriting occurs, the old data is essentially destroyed and irrecoverable. There is no way for recovery software to bring it back, since the 1s and 0s that comprised the original file no longer exist.
How does undelete software recover deleted files?
File recovery programs scan your hard drive looking for intact traces of deleted data. They examine the raw 1s and 0s for patterns that would indicate a recoverable file. When matches are found, they rebuild the files so you can access them again.
Different recovery software uses various methods to find deleted data. Some directly analyze the hard drive’s sectors, while others work from the file system tables that track file locations. The best ones utilize several techniques to maximize the chance of finding recoverable data.
What are the chances of recovering a deleted file?
If you act quickly before the deleted file’s original location on your hard drive is overwritten, the chances of full recovery are good. However, the likelihood drops steadily as new data is saved that could be occupying the same disk space.
In general, deleted files are highly recoverable if you attempt restoration within a day or two. After a week, less data will be retrievable as some overwriting is likely to have occurred. Beyond two weeks, the odds are slim unless very little new data has been added.
How long does data remain before overwritten?
There is no set timeframe after which deleted files are guaranteed to be overwritten. It depends entirely on how actively you continue using the computer and saving new files. If your usage is minimal, deleted data could potentially remain recoverable for months. But with frequent use and data storage, critical overwriting could happen in days or less.
Quickly overwriting deleted files is more likely on a heavily-used system. This is especially true if it has a solid state drive vs. a traditional hard disk drive. SSDs have performance optimizations that encourage overwriting versus just appending data. You typically have less time to recover deleted files from SSDs compared to HDDs.
Can you recover permanently deleted files?
When a file is permanently deleted, either through bypassing the Recycle Bin or using Shift + Delete, it works similarly to a standard delete. The reference is removed immediately, while the 1s and 0s remain intact until overwritten.
The main difference is that you lose the window of opportunity to undelete through the Recycle Bin. But permanent deletion does not make file recovery impossible. As long as the original data still exists unaltered on the hard drive, data recovery software can restore permanently deleted files.
What files types can be recovered?
Nearly any deleted file can potentially be recovered as long as its data remains intact and un-overwritten on the hard drive. This includes:
- Documents – Word, PDF, Excel, etc.
- Photos – JPG, RAW, PNG, etc.
- Video & Audio – MP4, MOV, MP3, etc.
- Archives – ZIP, RAR
- Emails
- Database files
- System files
- Applications
As long as the core data exists untouched in its original location, the file can likely be restored. The file extension helps identify the format, but the content itself allows the file to be rebuilt.
What are the chances of recovering different file types?
The likelihood of recovering a deleted file depends far more on when it was deleted and the level of hard drive overwriting than the specific file type. However, there are a few generalities:
- Text documents have very high recovery rates since they take up little space.
- System and application files are often overwritten quickly, reducing recoverability over time.
- Media files like photos, video, and audio have good recovery rates if you act fast.
- Database files and emails often reside in frequently accessed folders, increasing overwriting risk.
- Archives take up more drive space, increasing the chance of some data loss over time.
But again, recovery depends much more on how quickly you attempt it and the degree of overwriting than the category of file. Any file has a strong chance if undeleting occurs rapidly.
Can you recover files after reformatting a hard drive?
When you reformat a hard drive, it wipes the slate clean by erasing the file system information and reconfiguring the disk’s format. This makes your existing files seem to vanish since the operating system loses all the references to their locations.
However, reformatting doesn’t immediately overwrite all the existing 1s and 0s on a drive. It simply clears the file allocation tables and marks the previously occupied space as free for new data. The actual file contents often remain intact until the reformatting process writes new files over them.
So recovery software still has a chance of undeleting your files after reformatting, as long as the sectors storing them aren’t overwritten by adding new files. However, you’ll have a limited window before extensive overwriting is likely to occur. So recover promptly.
Can files be recovered after a disk wipe?
A disk wipe goes beyond reformatting to actively overwrite all existing data with meaningless 1s and 0s. This aims to completely scrub any residual traces of deleted files and previously stored data.
After even a single pass file wipe, recovery becomes virtually impossible. The original data has been actively destroyed by the comprehensiveoverwrite rather than simply de-referenced as with reformatting.
A multi-pass random wipe is considered unrecoverable. The only hope lies with traces that might potentially persist on the raw disk platters at a sub-sector level. But no consumer software can meaningfully recover user files after a professional disk wipe.
Top deleted file recovery software
Here are some of the most widely used, trusted, and capable data recovery programs to restore accidentally deleted files:
1. Disk Drill
Disk Drill offers top-rated undelete capabilities with an easy graphical interface. Both quick and deep scan options allow recovering lost files from internal drives, external disks, USB drives, SD cards, etc. Works on Windows & Mac.
2. Recuva
Developed by Piriform, Recuva is a leading free file recovery tool for Windows, with support for portable media and drives. Offers simple wizard-based scanning and ability to preview found files.
3. EaseUS Data Recovery Wizard
EaseUS provides reliable, full-featured recovery of deleted files from hard drives, SSDs, USB, SD cards, etc. Works on Windows and Mac with an easy step-by-step recovery process and deep scan support.
4. Stellar Data Recovery
Stellar Data Recovery performs safe, complete recovery of lost documents, images, video, and other file formats from Windows and macOS. Features include cloning for unbootable drives and advanced photo recovery.
5. R-Studio
R-Studio provides professional-level data recovery including RAID reconstruction, advanced scanning, and complex file recovery from formatted or damaged media. Supports Windows, Mac, and Linux.
6. Ontrack EasyRecovery
Ontrack EasyRecovery can recover deleted files from hard drives, SSDs, USB drives, SD cards, etc. Features include free preview of found files, rebuilding RAID arrays, and rescue options for inaccessible media.
How to choose the best deleted file recovery software
Key factors when selecting undelete software include:
- Supported devices and filesystems – Can it recover data from hard drives, SSDs, USB, SD cards, external drives, etc.
- Scanning capabilities – Does it have quick and deep scanning options to uncover even buried deleted files.
- File previews – Can you view found files before deciding to recover them.
- Ease of use – Is the interface intuitive to navigate and recovery process straightforward.
- File filtering – Can you filter scans by specific file types or search for files.
- Recovery features – Specialized features like RAID, partition, or photo recovery can be useful.
- Technical support – Is knowledgeable support available if needed.
- Cost – How much does the software cost to install or own.
The right choice also depends on your use – whether you need recovery for occasional home use or plan to offer professional file recovery services.
How can you avoid needing file recovery in the future?
Some things you can do to avoid needing deleted file recovery include:
- Be more careful when deleting files to avoid mistakes.
- Backup important files so you have another copy if needed.
- Disable Recycle Bin deletion confirmations to avoid permanent deletion.
- Use versioning or previous versions to recover older copies of Word/Excel documents.
- Turn on Windows File History or Mac Time Machine for easy point-in-time recovery.
- Use cloud backup services like Dropbox that retain deleted files for a time.
Prevention is the best solution. But if you ever do need to recover lost files and documents, undelete software gives you an excellent chance as long as you act fast to avoid data overwriting.
Conclusion
While file recovery is never guaranteed, deleted data that remains intact in its original location is highly recoverable. The right software makes finding and restoring previously deleted files a straightforward process. Just be sure to use it promptly before that content has been overwritten. With the help of the best data recovery solutions, your chances of getting important files back are very high.