Fix External Hard Drive Not Initialized, I/O Device Error without Losing Data

Tracy King updated on Jan 22, 2021 to Storage Media Recovery | How-to Articles

To fix 'Disk Unknown Not Initialized' error on an external hard disk, you should initialize the disk at first. Some succeed, but some fail due to a successive error message 'the request could not be performed because of an I/O device error'. This page is to solve this type of [external hard disk not initialized I/O error]. Data recovery is a safe move to the troubleshooting part, and EaseUS hard drive recovery software can handle it well.

Overview: external hard disk not initialized I/O error

What are the reasons that cause hard drive or external hard drive showing unknown not initialized on your PC? Here is a list of known factors:

  • Virus attack
  • Bad sectors
  • Partition Loss
  • File system corruption
  • Corrupted Master Boot Record (MBR)

Symptoms of the disk not initialized:

  1. 1. Disk shows as Unknown, Not Initialized with unallocated space.
  2. 2. Disk shows as Unknown, Not Initialized with no space displayed.

What's I/O error?

An I/O device error, short for Input/Output device error, happens when Windows is not able to perform an input/output action (such as reading or copying data) when it is trying to access a drive or disk. It can occur to many different types of hardware devices or media.

To fix 'Disk Unknown Not Initialized' error on an external hard disk, you should initialize the disk to GPT or MBR at first. Some succeed, but some fail due to a successive error message 'the request could not be performed because of an I/O device error'.

disk unknown not initialized i/o error

Combining the two consecutive error messages, here you are. When initializing a disk fails and you're caught up in the other unfamiliar I/O error, where is the way out? This page is to solve this type of [external hard disk not initialized I/O error].

Part 1. Recover data from external hard drive unknown not initialized I/O error

You should know that initializing a disk won't damage data, causing data loss problem at all. It's safe to initialize a disk to a normal state when it shows as unknown not initialized. 

To initialize a hard disk in Windows Disk Management:

Step 1. Connect the uninitialized external hard drive, HDD or other storage devices to your PC.

Step 2. Press Win + R keys to bring up Run, and type: diskmgmt.msc and hit Enter.

open disk management in Run box

Step 3. Find the uninitialized, unknown external hard drive with I/O device error > Right-click on it and select Initialize Disk.

Step 4. Then set the disk to initialize and set the disk as MBR or GPT.

initialize external hard drive to mbr or gpt to fix unknown not initialize error

However, this time is different. You cannot perform the manner of initializing a disk because of I/O error. So, you must turn to other workarounds instead of the most approachable one. Fixes beyond initialization could bring data loss, and it's smart for you to recover data from the inaccessible external hard drive before heading to the troubleshooting in Part 2.

EaseUS Data Recovery Wizard is renowned hard drive data recovery software, it's able to recover all types of files, like pictures, raw images and documents from a variety of storage devices, as long as the hard drive itself can be detected by Windows. If the hard drive is not showing up in Disk Management, try to make it visible.

To recover data from external hard drive with I/O error:

Step 1. Choose the external hard drive

Since you're going to recover data from the external hard drive, run EaseUS Data Recovery Wizard and choose the exact drive where you lost data. Click Scan.

select external hard drive

Step 2. Scan for lost data

The software will start immediately to scan all over the selected drive for all lost data. During the scan, you could see more and more data showing up in the results.

scan external hard drive

Step 3. Preview and recover data

After the scan is over, check the scan results for the desired data. You can preview the file by double-clicking on it. Click Recover and choose another location to save the recovered data.

preview and recover data

Part 2. Fix external hard drive not initialized with I/O device error

You're going to get rid of such pesky issue and fix external hard drive not initialized I/O error by going to [1] change a connection cable, [2] fix corrupted MBR, [3] use DiskPart command, and [4] remove virus from your PC/laptop.

The fix 2 and fix 4 are available on the linked pages, so we provide the detailed steps of how to use DiskPart command to clean the external hard drive. Since the CMD command would erase all data on the uninitialized hard drive, if you didn't recover data in advance, go to Part 1 to restore lost data after repairing the external hard drive not initialized error with DiskPart commands.

To clean the external hard drive with DiskPart:

Step 1. Press Win+R > Type: diskpart and hit Enter.

Step 2. Type: list disk and hit Enter.

Step 3. Type: select disk n and hit Enter; (replace n with the drive letter of an uninitialized external hard drive.)

Step 4. Type: clean and hit Enter.

Step 5. Type: convert gpt or convert mbr and hit Enter.

Step 6. Type: create partition primary and hit Enter.

Step 7. Type: format quick fs=ntfs and hit Enter.

Step 8. Type: assign and hit Enter.

Step 9. Type: exit and hit Enter.

Here, click to copy all the required command lines to fix an external hard drive not initialized I/O error, with the full error message 'the request could not be performed because of an i/o device error'.

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Frequently Asked Questions

1. Why choose EaseUS Data Recovery Wizard?

"EaseUS Data Recovery Wizard is the best we've seen. It's far from perfect, partly because today's advanced disk technology makes data-recovery more difficult than it was with the simpler technology of the past, but it's fast and efficient..."PCMag

"The first thing you'll notice about EaseUS Data Recovery Wizard Pro is that its interface is very clear and uncluttered, with only a small collection of self-explanatory controls. You won't find lots of extra options hidden in a system of hidden menus, either; what you see really is what you get."techradar

"Recover lost files, even after deleting a partition or formatting your drive."Macworld

2. Why cannot I recover 2GB data for free?

It is recommended to check the version installed is Free or Trial because they are different versions.

Trial has data preview function but cannot save any files, while the Free version enables to recover 2 GB files. The default free space is 500 MB and you may share the product on social media to get another 1.5 GB.

3. Why cannot the recovered files be opened?

A file is saved as 2 parts on the storage device: directory info (which is comprised by file name, time stamp and size info, etc.) and data content.

If the files with original file names and folder structures cannot be opened, one possible reason is the corrupted directory info. There is still a chance to recover the data content with the RAW Recovery method in our software.

4. Why isn't it suggested to recover the files back to the original drive?

The storage structure of the lost files would be altered or damaged by any changes on the drive. If you save the recovered files back to the same drive, the original data structures and data content would be corrupted or overwritten, which causes permanent data loss. So you should prepare another disk to save the files.

5. How can I check whether my data is recoverable or not before purchase?

The Free version helps you save 2GB files, so verify the recovery quality of our product before purchase.

6. How long does it take to scan the drive?

It strongly depends on the capacity of your hard drive and the performance of your computer. As reference,most drive recoveries can be completed in around 10 to 12 hours for a 1-TB healthy hard drive in general conditions.

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