CHKDSK is a utility built into Windows that can check your hard drive for errors and attempt to repair them. But can it actually fix a failing or failed hard drive and recover lost data? Let’s take a quick look at what CHKDSK does, when you should use it, and whether it can resurrect a dying hard drive.
What Does CHKDSK Do?
CHKDSK examines the file system and structure of your hard drive and looks for a variety of errors and problems, including:
- Bad sectors – areas of the drive that are physically damaged
- Cross-linked files – files that are incorrectly linked to other files or directories
- Invalid file records – file system entries that point to invalid locations
- Orphaned files – files not linked to any directory
- Directory errors – incorrect or looped directory structures
- Lost clusters – sections of the drive that are not allocated properly
When CHKDSK encounters these types of errors, it will attempt to repair them. For example, it can:
- Mark bad sectors as unavailable so they won’t be used
- Remove invalid file records
- Put orphaned files into a new folder (FOUND.000)
- Realign directory structures
- Re-allocate lost clusters so they can be used again
In addition to fixing errors, CHKDSK will also recover readable information from bad sectors and make it available again.
So in summary, CHKDSK examines the structure of your hard drive, fixes logical file system errors, recovers readable data from bad sectors, and marks damaged areas as unavailable. This allows your drive to function better and prevents data loss.
When Should You Run CHKDSK?
You should use CHKDSK if you suspect logical file system errors on your drive, which can cause a variety of problems including:
- Slower drive performance
- Long delays when accessing files and folders
- Frequent error messages
- Inability to access files and data
- Unstable computer operation
- Frequent crashes and freezes
These types of issues may indicate logical errors that CHKDSK can detect and repair. Running CHKDSK regularly as a preventative measure is also a good idea, as it can fix minor errors before they become major problems.
However, CHKDSK is not a data recovery tool. If you have already lost access to files or partitions on your drive, CHKDSK will not be able to recover deleted files for you. A dedicated data recovery tool is required for that job.
Can CHKDSK Fix a Physically Damaged Drive?
This is where things get tricky. If your hard drive has already physically failed or is failing – for example, if it has head crashes, motor or PCB failure – CHKDSK cannot fix those types of mechanical problems. It is designed to fix logical file system errors only.
However, CHKDSK can potentially get a failing drive into a temporary working state again by marking damaged areas as unavailable. For example, if your drive has bad sectors starting to spread across the platters, CHKDSK could mark those sectors as bad, allowing the remaining good areas to be accessed again.
But any repair would only be temporary. The mechanical damage will continue to get worse over time until the drive completely fails. CHKDSK cannot reverse the physical deterioration of a dying hard drive.
Some other examples where CHKDSK may help prolong the life of a failing drive:
- Marking an increasing number of bad sectors as unavailable to prevent their use
- Realigning directory and file system structures that have become corrupted
- Recovering readable data from newly damaged areas to minimize data loss
So while it cannot completely fix a mechanically failing drive, CHKDSK can potentially buy you some extra time in certain situations to backup your data before the drive dies completely. But it’s important to understand it is only a temporary fix, not a long-term solution for a failing drive.
Can CHKDSK Recover Lost Files and Partitions?
As mentioned earlier, CHKDSK is not designed as a data recovery tool. It cannot recover deleted files or partitions for you.
If you have accidentally deleted files that were on a healthy drive, a dedicated undelete tool may be able to get them back as long as the drive space they occupied has not been overwritten.
And if you have accidentally reformatted a drive or deleted a partition, data recovery software that can scan the raw sectors may be able to rebuild the old file system and recover your files, as long as the original data was still intact.
But CHKDSK does not have specific capabilities to recover lost files, folders or partitions. Its abilities are limited to fixing logical file system errors rather than restoring lost data.
The one exception is that if CHKDSK is repairing a drive that has newly developed bad sectors, it can recover the readable data from those sectors before marking them as damaged. But it does not have the capability to restore previously deleted files.
Should You Run CHKDSK on an External Drive?
CHKDSK can certainly be used on external hard drives like USB HDDs and SSDs if you notice signs of file system corruption or errors. Just like on an internal drive, it may be able to repair logical issues and prolong the life span of the drive.
However, you do need to be a bit careful before running CHKDSK on an external drive, especially if it is the only copy of your important data. That’s because major CHKDSK operations like /f or /r options can temporarily make your files unavailable as the drive is being repaired.
So it’s a good idea to only perform surface-level checks using the basic /f command first without any repair options like /f or /r. Review the report to see if any errors are reported. If so, backup your external drive data to another location before using the repair options.
You may also want to consider using the /scan option first to just scan for errors without trying to repair anything. Then you can backup as needed before doing repairs.
Can CHKDSK Be Used on SSDs?
CHKDSK can be used to detect and repair file system errors on newer solid state drives (SSDs) as well. However, the way it functions has some key differences compared to a traditional hard disk drive:
- It will not detect or mark bad sectors on an SSD. Wear leveling makes bad blocks irrelevant on flash memory.
- No data will be recovered from worn out cells since SSDs don’t store readable residual data.
- No surface scan will be performed. SSDs don’t have physical heads to check.
But CHKDSK still serves an important role on SSDs by fixing logical file system errors like cross-linked files, directory errors, invalid records, orphaned files, etc. This helps ensure maximum performance and data integrity across the drive.
CHKDSK is less crucial on SSDs since they are less prone to physical failure over a traditional HDD. But it’s still a valuable tool to optimize your SSD by repairing file system errors that can accumulate over time.
How Long Will CHKDSK Take?
The amount of time CHKDSK will take to complete depends on various factors:
- Drive size – larger drives take longer to scan and repair.
- Errors – more errors means a longer repair time.
- File system – NTFS takes longer than FAT32.
- Options used – a full scan and repair takes longer than a basic scan.
- Drive health – CHKDSK takes longer on damaged drives.
On a healthy 1TB drive, a simple CHKDSK /f scan may only take a few minutes. But a full /f /r scan on a 6TB drive with lots of errors could take many hours to complete. There’s no definitive time frame since each situation is unique.
The key is to be patient and avoid interrupting CHKDSK before it finishes. An incomplete CHKDSK run can leave your drive in a corrupted state. Let it run overnight if needed.
Can You Use CHKDSK on the Active System Drive?
You can run CHKDSK on the current “live” boot drive, but with limitations:
- You won’t be able to scan/repair file system errors on the active partition.
- You can only check/repair errors on inactive partitions.
- You may miss errors only visible when the OS is not accessing the drive.
For the most comprehensive scan, you should run CHKDSK from a boot CD or external drive so the system partition is inactive and fully unmounted from the OS. This provides full read-only access to scan over the drive.
However, you can perform a more superficial CHKDSK scan from within Windows to check the inactive partitions on your system drive. Just don’t expect a full repair until you can boot from separate media.
How to Use CHKDSK in Windows
Using CHKDSK is easy. Here are the basic steps:
- Open an elevated Command Prompt window.
- Type “chkdsk” and hit enter to start a read-only surface scan.
- Use “chkdsk C: /f” to scan drive C: and fix errors.
- Add “/r” to locate bad sectors and recover readable data.
- Add “/x” to dismount the drive before scanning (if not the system drive).
- Add “/scan” to just scan for errors without repairing.
So for example, “chkdsk C: /f /r /x” will do a full dismounted scan of C: drive and attempt to fix errors and recover data from bad sectors.
See Microsoft’s documentation for more details on using the various CHKDSK parameters and switches. And remember that while this built-in tool is handy for minor drive issues, for more advanced hard drive recovery you’ll need a dedicated data recovery program.
Conclusion
While CHKDSK cannot completely fix or repair a physically failing hard drive, it can fix logical file system errors and prolong the life of a drive with bad sectors. By marking damaged regions as unavailable and recovering readable data, CHKDSK may buy you some extra time to backup your data before the drive fails completely. But it’s still just a temporary fix, not a way to fully resurrect a dead drive. And CHKDSK should not be used for lost file recovery, which requires dedicated undelete software. Use CHKDSK as one part of your hard drive maintenance routine, but don’t rely on it alone to save a dying drive.