By Lily / Last Updated July 20, 2020

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The scenario


I'm using 80GB external hard disk for my study use. When I brought it to my Uni's computer lab today, it was hang and without access. It showed the message ‘the file or directory is corrupted and unreadable’. Could you please let me know what the matter is with my hard disk? I don't have any backup. It's so awful for me to lose the information stored in my hard disk.... please... I need help....”

External hard drives can become corrupted or not accessible due to various reasons, such as file system error, bad sectors, virus attack, sudden ejection or other improper operations. Reformatting the hard drive can fix any non-physical errors on the drive. Nevertheless, all contents will be erased in the formatting process. Can we fix a corrupted external hard drive without formatting? Surely we can!

How to repair a corrupted external hard disk without formatting in Windows?

To repair a corrupted external hard disk without formatting, you can make use of the CHKDSK utility which scans through your entire hard drive to find and fix problems. CHKDSK should be opened in CMD. Learn how to fix a corrupted hard drive using CMD below:

1. Tap the Search button on the taskbar and type “cmd” in the search box. Right click “cmd” and then select “Run as administrator”.

2. Type chkdsk F: /f /r /x and press Enter. F is the drive letter of the corrupted external hard drive.


Tips: The meaning of the parameters used—“/f” tells chkdsk to fix any errors it finds; “/r” tells it to locate the bad sectors on the drive and recover readable information; “/x” forces the drive to dismount before the process starts.

3. Type exit and press Enter to exit Command Prompt.

Note: If the external hard drive becomes RAW due to certain damages, you may encounter the error that CHKDSK is not available for RAW drives. In this situation, you can use a professional data recovery tool like Recoverit Pro to recover data from the corrupted drive to another place and then format the drive to make it usable again.

Alternative way to repair a corrupted hard disk without formatting

How to repair a corrupted hard disk without formatting? Backup, the most fundamental disaster recovery technology, is the answer. If you make a backup for your external hard drive, you can restore it to normal state when it gets corrupted. The recovery process will bring you back not only a working drive but also all the data stored on it when the backup is made.

Here I’d like to recommend the best free backup software—AOMEI Backupper Standard to you. It enables you to perform full system backups as well as backing up specific files, documents, disks and partitions. To ensure your backups are kept up to date, you can schedule backups so they happen automatically. Learn how to backup an external hard drive via AOMEI Backupper in detail below:

1. Connect the external drive to your computer and make sure it is detected. Download, install and run AOMEI Backupper.

2. Click Backup on the left pane and select Disk Backup.

Disk Backup

3. Click Add Disk to select the external drive as the source disk to be backed up.

Select External Disk

4. Click the folder shaped button in the second column to select the destination path to save the image backup.

Select Destination Path

5. Click Start Backup to run the backup. Safely disconnect the drive when the backup is finished.

Start Backup


  • Options: you can enable email notification, choose the compression level for the backup image file and select intelligent sector backup or sector-by-sector backup.

  • Schedule: you can set the backup task to run automatically at fixed intervals.

  • Scheme: it will delete old image files automatically to save disk space for you. This feature is supported by AOMEI Backupper Professional and higher editions.

With the disk backup at hand, you can fix a corrupted external hard drive without formatting easily by performing disk restore.


Now you know how to fix a corrupted external hard drive without formatting in Windows. Both the CHKDSK utility and AOMEI Backupper can give you a hand. Besides the backup & recovery functions, AOMEI Backupper owns the clone feature. You may use it to clone the system or disk when Paragon Migrate OS to SSD stuck or Samsung Data Migration BitLocker cloning failed.