How to fix unallocated external hard drive without losing data?

Posted by Molly to Data Recovery Tips on September 5th, 2018

I am using my external HDD last night, it was attached to my CPU and suddenly my computer turned off without unplugging my external HDD. This day I tried to attach my external HDD but it was not showing on my computer. Lately found out that my external HDD is "unallocated". Is there any way to fix unallocated external hard drive without losing data?

Unallocated space of external hard drive refers as free space. However, this free space should be "allocated", or formatted with a proper file system, before the operating system can read, write to it and store data on it. What if the unallocated external hard drive contains tons of important data such as videos, audio, documents, images and much more? In this article, we will show you fix unallocated external hard drive without data loss.

Why does an external hard drive become unallocated?

There are many known and unknown reasons that may lead to an external hard drive unallocated. Some of the common issues include:
1. External hard drive file system corruption or damage;
2. Improper ejection of the external hard drive;
3. External hard drive partitions were created or modified incorrectly;
4. External hard drive's driver outdated;
5. Hardware failure;
6. Mistakenly deleted volume;
7. Virus infection or malware attacks; etc.

The external hard drive will be inaccessible after becoming unallocated, so is the data stored on it. But you can breathe with a relief because the data is still there and recoverable, as long as no further operation has been made to the unallocated external hard drive.

How to fix unallocated external hard drive without losing data?

As mentioned above, to fix an unallocated external hard drive, you need to format the external hard drive with a file system, such as formatting to NTFS, FAT32, exFAT, etc. But with important data on the drive, the most reliable solution we'd like to suggest is, first of all recovering data from the unallocated external hard drive, then fix the unallocated external hard drive.

Step 1: Recover lost data from unallocated external hard drive.

Professional external hard drive data recovery software like iBoysoft Data Recovery can help recover lost data from unallocated external hard drives without data loss.

iBoysoft Data Recovery is able to recover lost data from not working external hard drives after power failure, recover lost data from unrecognized external hard drive after accidental unplugging, and recover lost data from formatted, corrupted, dead, RAW, inaccessible external hard drives, USB drives, SD cards, memory cards, Pen drives, and other external storage devices.

Follow the steps to recover lost data from unallocated external hard drive with iBoysoft Data Recovery.

1. Free download iBoysoft Data Recovery and install it on Windows 10.

2. Launch iBoysoft Data Recovery.

Recover lost data from unallocated external hard drive with iBoysoft Data Recovery

3. Select the unallocated external hard drive and click "Next" to start scanning for all lost files.

4. Select the files you want to get back and then click "Recover".

Step 2: Fix unallocated external hard drives by formatting.

1. Type "cmd" in the search bar from Start, find Command Prompt application and right-click on it, select Run as administrator.

2. Type in "diskpart" and hit Enter.

3. Type in "list volume" and hit Enter.

4. Type in "select volume F" and hit Enter. Please replace F with the drive letter of the unallocated external hard drive.

5. Type in "delete volume override" and hit Enter.

6. Go to Disk Manager and select the unallocated space or free space.

7. Right-click on it and select Create New Simple Volume.

8. Follow the wizard to complete the process.

In this way, you can fix unallocated external hard drive without losing data. Now you can copy back the recovered data to the allocated or properly formatted external hard drive.

Still have questions?