Should I scan and fix external hard drive?

Quick Answers

Scanning and fixing an external hard drive can help resolve a number of issues and prevent data loss. However, it is not always necessary. Here are some quick answers:

  • If your external hard drive is running slowly or freezing, scanning and fixing it can help identify and repair errors.
  • If you are getting read/write errors or file corruption, a scan and fix may resolve these problems.
  • Before reformatting an external hard drive, try scanning and fixing it first as this may resolve performance issues.
  • Periodically scanning external hard drives can help identify potential problems before they lead to data loss.
  • If your hard drive does not show signs of errors, scanning and fixing it is not essential but can still be beneficial for maintenance.

What Issues Can Scanning and Fixing Resolve?

Scanning an external hard drive analyzes the disk for errors and attempts to repair them. Fixing errors prevents common problems like slow transfer speeds, freezing, crashing, read/write errors, and file corruption. Here are some specific issues that scanning and fixing can help identify and resolve:

Bad Sectors

Bad sectors are areas on a hard disk that have become physically damaged and unusable. They can lead to data corruption and freezing. Scanning locates bad sectors so they can be marked and avoided. If the damage is repairable, fixing may recover these sectors.

File System Errors

File system errors occur when key data structures that organize files on your drive become corrupted. Scanning diagnoses file system problems like bad clusters and misallocated space. Fixing repairs the structured to restore proper file organization.

Outdated Firmware

Firmware is low-level software that controls hardware function. Outdated firmware can impair drive operation and compatibility. Scanning checks firmware status and fixing updates firmware if needed.


Fragmentation happens when pieces of files are scattered across the hard disk. This slows down file access and operations. Defragmenting during a fix reorganizes files into contiguous regions to optimize performance.

Registry Errors

The registry stores system configuration data for Windows. Errors here can cause crashes and hardware issues. Scanning diagnoses registry problems, and the fix restores proper registry entries.

Driver Issues

Drivers allow the operating system to communicate with hardware devices. Outdated or corrupted drivers can impair external hard drive function. Scanning checks driver status, and fixing updates or reinstalls them.

When Should I Scan and Fix an External Hard Drive?

Scanning and fixing an external hard drive is especially useful in the following situations:

  • Slow performance: If programs, files, and operations are taking much longer than normal, scanning can identify errors causing the lag, and fixing will improve speed.
  • Frequent freezing/crashing: Scans can pinpoint problems leading to system instability, and fixes address these issues to restore normal function.
  • Read/write problems: Inability to open or save files points to read/write head or media surface issues. Scanning diagnoses these physical problems, while fixing marks out defective areas.
  • File/data corruption: Unreadable files and data errors indicate file system or bad sector problems. Scanning locates any corruption, and fixing repairs the files and structures.
  • Before reformatting: If you are planning to reformat due to performance issues, try scanning and fixing first, as this may resolve problems without erasing your drive.
  • Strange behaviors: Unusual activity like disappearing files, strange noises, and program issues can signify drive problems. Scan to identify any problems, and fix them.

How Do I Scan and Fix an External Hard Drive?

Scanning and fixing an external hard drive is a straightforward process. Here are the steps to follow:

  1. Backup your data: As a precaution, backup all important files on the drive before beginning.
  2. Connect the drive: Make sure the external drive is connected to your computer via USB, eSATA, Thunderbolt, or FireWire.
  3. Download software: Download drive utility software that has scan and fix features, such as Drive Genius, Disk Drill, or HD Tune.
  4. Select scan feature: Open the drive utility program, select the external drive, and choose the “Scan” option.
  5. Run the scan: The software will begin analyzing the drive to identify any problems. This may take a while for large drives.
  6. Review scan results: Once complete, the software will report identified errors like bad sectors, file system corruption, physical damage, etc.
  7. Select fix feature: Choose the “Fix” or “Repair” option in the drive utility software.
  8. Perform the fix: The software will repair any found errors by correcting file system problems, updating firmware, relocating data from bad sectors, etc.
  9. Re-scan if needed: After fixing, re-scan the drive to check if any problems remain. Repeat fixing until no more errors are found.

What Problems Can’t Be Fixed by Scanning?

While scanning and fixing resolves many external hard drive issues, some problems cannot be repaired this way, including:

  • Physical damage: Severe physical damage to the drive mechanics/electronics from impacts can render it nonfunctional. Scanning cannot fix these hardware problems.
  • Deleted data: Scanning cannot recover previously deleted files and data. This requires data recovery software.
  • Partition loss: Lost or deleted partitions cannot be restored via simple scans and fixes. Partition recovery software is needed.
  • Logical damage: Viruses, failed firmware updates, or incorrect configurations can cause logical damage. Low-level disk repair is required.
  • Mechanical failure: If the read/write heads, motor, or bearings fail mechanically, the hardware must be replaced or professionally serviced.

If drive utility software cannot resolve your external hard drive problems, you may need professional data recovery or repair services for physical and logical issues.

Should I Scan and Fix an External Hard Drive as Preventive Maintenance?

Scanning and fixing external hard drives periodically can serve as beneficial preventive maintenance even if no problems are immediately apparent. Here are reasons to make it part of your regular upkeep:

  • Identify impending failure: Scans can detect read/write errors and bad sectors that could precede drive failure.
  • Resolve minor corruption: Small file system inconsistencies that could later cause bigger problems are repaired.
  • Defragment files: Defragmenting optimizes file storage and retrieval performance.
  • Update firmware: Firmware updates provide stability improvements and compatibility fixes.
  • Extend lifespan: Regular maintenance helps the drive operate smoothly, potentially extending its lifespan.
  • Prevent data loss: Finding and fixing issues early prevents major file system corruption or physical damage that leads to data loss.

Ideally, external hard drives should be scanned and fixed every few months as part of standard maintenance procedures.

External Hard Drive Scanning and Fixing Tips

Follow these tips for effective external hard drive scanning and fixing:

  • Choose reputable drive utility software from established vendors.
  • Update your antivirus software first to avoid conflicts during scanning.
  • Schedule scans when you do not need immediate access to the drive.
  • Select “deep scan” or “full scan” options for a thorough analysis.
  • Review scan logs carefully to identify areas needing repair.
  • Research errors reported by the software to understand their implications.
  • Begin by trying the automatic repair option before attempting manual fixes.
  • Backup important data and partitions before attempting fixes that modify the drive.
  • Re-scan after fixes to ensure errors have been properly corrected.
  • Compare scan results before and after fixing to evaluate improvements.

Frequently Asked Questions

Why does my external hard drive need scanning and fixing?

External hard drives can develop various problems like bad sectors, file system corruption, fragmentation, and physical damage over time. Scanning locates these issues, while fixing resolves them to restore optimal performance and data integrity.

When should I scan and fix my drive?

You should scan and fix your external hard drive if you notice slow performance, freezing, file corruption, strange behaviors, read/write errors, or as part of periodic preventive maintenance every few months.

What problems will scanning and fixing repair?

Scanning and fixing will resolve file system errors, bad sectors, fragmentation, corruption, outdated firmware, drive errors, and minor physical damage that impairs drive function and data access.

What damages cannot be repaired by software fixes?

Severe physical damage, mechanical failure, logical/electronic issues, deleted data, lost partitions, viruses, and major corruption typically require professional data recovery or repair services, not just drive utility software.

Is scanning and fixing external drives safe?

Drive utilities from reputable vendors are generally safe to use. However, backups are recommended, and you should research any errors found before attempting fixes that modify the drive structure.

How long does scanning and fixing take?

Scan and fix times vary based on drive size and the number of errors found. Scanning typically takes 1-5 hours. Fixing can add 1-3 hours. Larger drives with lots of errors can take up to 10+ hours to complete.

Will scanning or fixing erase my drive data?

No, scanning should never erase or modify data. Fixing rarely erases data unless critical file system structures are damaged. However, crucial backups are still recommended before any fixing.

Do I need special software to scan and fix drives?

Yes, you need proprietary drive utility software designed specifically for diagnosing and repairing hard drive problems. Popular options include Drive Genius, Disk Drill, Spinrite, and HD Tune.


Scanning and fixing external hard drives is an important troubleshooting step when performance issues arise, and a useful periodic maintenance procedure to help prevent problems. Quality drive utilities can resolve many common errors and restore optimal function. However, physical damage may require professional data recovery, so research any persistent issues thoroughly. With proper tools and understanding, most external hard drive problems can be successfully diagnosed and repaired by an informed user.