[Solved] Disk Unknown Not Initialized in Windows 10/8/7

Generally, if your disk shows not initialized, it's probably caused by MBR corruption or physical damage. If your disk becomes unknown and not initialized and shows as unallocated space, you can initialize the disk and then recover data with EaseUS Data Recovery Wizard to fix the issue. If Disk Management shows no information about your disk capacity, you will need other fixes provided to have a try.

Table of Contents

Solution 1, solution 2, and Solution 3 apply to fix disk is not initialized and shows unallocated. And Solution 4, solution 5, and solution 6 use to fix disk is not initialized and shows nothing about disk capacity. You may follow the quick guide:

Disk 1 Is Unknown, Not Initialized, Unallocated

"When I plugged in my external hard drive, Western Digital My Passport 0740 (500GB), PC said that it's successfully installed however it did not appear on My Computer. Also when I went into system tools it said that disk 1 is unknown, not initialized, unallocated. Does anyone know how to recover data when a hard drive is not initialized or how to initialize disk without losing data?"


Like the case above, "Disk Unknown Not Initialized" issue usually attacks unexpectedly in all the Windows version, including Windows 10, 8, 7, and annoys numerous users. When it happens, your external hard drive may show "unallocated space" or nothing about the disk capacity in Disk Management (like in the image below), so you are not able to open and access the data on this disk.

Disk Unknown Not Initialized


Although the disk shows "Unknow, Not Initialized" in both of the situations. They present different information about the capacity of the hard drive, which means they are caused by different reasons.

If "disk unknown not initialized" is accompanied by "unallocated", the cause is likely to be MBR corruption on the hard drive. MBR, Master Boot Record, is the first sector on an MBR or GPT disk. It provides information on loading Windows and on the partition of the disk. Thus, when it is corrupted, you will certainly encounter issues, including disk showing as "Not Initialized".

However, if your disk 1, disk 2, or another disk becomes "Not Initialized" without any information about the disk storage, the causes may be a connection issue, disk driver issue, or physical corruption on the disk.

How to Fix Disk Unknown Not Initialized in Windows 10/8/7

Depending on your situation, you will have different solutions to the problem "disk not initialized" on your computer, be it a local hard drive or external hard drive.

To fix a disk becoming "Not Initialized" in such a case, you can initialize the disk directly. Then here comes the question - does initializing a disk erase data? Actually, Initializing a disk will rebuild the master boot record. It WON'T ERASE the data on the disk. However, to make the disk usable again, you need to further partition and format the disk, which will erase the files on your hard drive. Thus, to fix "disk not initialized", you are recommended to :

  • Initialize the hard drive
  • Recover data from the disk and create new volumes
  • Partition and format the disk to make it ready for data storage

Solution 1. Initialize Disk

Applies to: Fix disk is not initialized and shows unallocated.

It is the easiest way to fix disk unknown not initialized issue.This also works to initialized a brand new hard drive.

Step 1. Just right-click "My Computer" > "Manage" to run Disk Management.

Step 2. Here, right-click the hard drive and click "Initialize Disk".

Step 3. In the dialog box, select the disk(s) to initialize and choose MBR or GPT partition style.

Initialize the hard drive to fix disk unknown not initialized error

After initializing the disk, you can now recover data from your disk. Based on your needs, you can either recover data only from the disk or recover both the partitions and the files on it.

Solution 2. Recover Data from Hard Drive and Create New Volumes

Applies to: Fix disk is not initialized and shows unallocated.

Here, if you have important files on the external hard drive, you can try the hard drive recovery software - EaseUS Data Recovery Wizard to recover the files from the inaccessible disk.

Step 1. Run data recovery software to scan data.

Select the location of your hard drive/external hard drive. The not initialized partition could be named as "Lost Partition" in the user interface. Click "Scan" to start scanning lost data on the hard drive. 

select a location and click scan

Step 2. Filter wanted files.

Once the scanning process completes, you can quickly find your lost files by clicking "Filter".

select and fiter wanted files

Step 3. Preview and recover data.

You can double-click the found files one by one to preview. Afterward, select the items you want to retrieve. Click "Recover", choose a location to save the files, and then click "OK" to start recovering the selected content.

recover files from initialized drive

If you recover data only, you will need to partition the disk by yourself following the steps below.

Step 1. Right-click "This PC" and choose "Manage" > "Disk Management".

Step 2. Right-click the unallocated space and choose "New Simple Volume..."

Step 3. In New Simple Volume Wizard, click "Next" to continue.

Step 4. Follow the wizard to specify the volume size, assign a drive letter to the volume, and then format the partition.

Disk Not Initialized - Partition the disk

If you don't want to create partitions by yourself, you can recover partitions on your disk that shows "Not Initialized", which will help you restore the original partitions on the hard drive.

Solution 3. Perform a Partition Recovery 

Applies to: Fix disk is not initialized and shows unallocated.

Applies to: Fix disk is not initialized and shows unallocated.

Download and launch the reliable partition tool - EaseUS Partition Master on your computer. With it, you can recover the partition on your hard drive with ease.

Step 1. Launch EaseUS Partition Master on PC

Click on "Partition Recovery" at the top of the main window.

Run EaseUS Partition Master for partition recovery

Step 2. Select a hard disk to search for the lost partition(s)

Choose the hard drive disk or SSD where you lost partitions, and click "Scan".

Run EaseUS Partition Master for partition recovery

Step 3. Wait for the scanning process to complete.

This program will scan the whole disk with two modes - "Quick Scan" and "Deep Scan" to find all lost partitions and data for you.

  • Quick Scan will find your latest deleted partition with a fast speed.
  • Deep scan will scan and find more and earlier deleted partitions.
Scan lost partitions

Step 4. Select and recover lost partitions

1. Select the lost partition, marked as "Deleted" with previous Labels, capacity etc, and click "Proceed" to continue.
2. Click "Recover Now" to confirm and restore the lost partition.

Scan lost partitions

3. Click the "Execute Operation" button and click "Apply" to restore lost partition.

Scan lost partitions

Besides, you can also rebuild MBR to try to fix "disk unknown not initialized".

Situation 4. Check Disk Connection

Applies to: Fix disk is not initialized and shows nothing about disk capacity.

Minor connection issue can cause serious problems like the one in the discussion. To check the connection, you can:

  • Connect your Toshiba external hard drive to another USB port, including the rear ones, on your computer
  • Use the original cable to connect your hard drive
  • Use another cable to connect your Toshiba hard disk
  • Connect your Toshiba hard drive to another computer

Situation 5. Update Device Driver

Applies to: Fix disk is not initialized and shows nothing about disk capacity.

An outdated or corrupted disk driver may also be the culprit. Updating the device driver can be easily done in Device Manager.

Step 1. Right-click on "This PC" (in Windows 10) and choose "Properties".

Step 2. Click "Device Manager" then expand “Disk drives”. Find and right-click the problematic disk and select "Update driver"

Step 3. Click "automatically search for driver software online".

Step 4. Wait for the driver to be updated, then reboot your computer. Afterward, you can try to reconnect your USB drive to PC and check whether the USB drive shows up or not.

Disk Not Initialized - Update Device Driver

Situation 6. Send for Manual Repair

Applies to: Fix disk is not initialized and shows nothing about disk capacity.

Physical damage will inevitably result in serious issues on a storage medium, including "disk unknown not initialized". If the methods above fail to solve the problem for you, sending your device to professionals for manual repair is a good choice.

Extra Tip: How to Fix Cannot Initialize Disk in Windows

A common reason that leads to "disk unknown not initialized" is that you fail to initialize the drive with a message saying "The request could not be performed because of I/O error", which, afterward, will cause your disk to be shown as Unknown or Not Initialized.

When you can't initialize a hard disk, "disk unknown not initialized" is not the only issue that you may encounter. For the detailed explanation and corresponding solutions, go to the article about how to fix the i/O device error.

If the guide cannot help you solve the problem, you are highly recommended to ask help from experts for manual repair or directly replace it with a new disk.

The Bottom Line

Although initializing a disk won't erase data on the device, the further operations will. Thus, if you want to fix a disk that is not initialized without losing data. Data recovery software is needed. However, if your disk shows "Unknow, Not Initialized" due to physical corruption, no data recovery software will help and only manual data recovery services have the chance to rescue your files.

FAQs About Disk Is Not Initialized

1. How do I fix disk 1 unknown is not initialized?

As mentioned on this page, there are basically 6 ways that can work to help you fix Disk 1 Unknow is not initialized error. They are:

  1. 1). Initialize the disk with Disk Management
  2. 2). Recover data from the unknown hard drive and create new volumes.
  3. 3). Preform partition recovery from the unallocated & not initialized drive.
  4. 4). Check the hard drive connection
  5. 5). Update hard drive driver
  6. 6). Send the hard drive for manual repair.

For a detailed guide, you can rever to the main content on this page and try any method to make your disk work again.

2. How do I force a hard drive to initialize?

As for a new hard drive, you may directly follow the steps below to initialize it. 

As for a used hard drive, you may need to copy or back up all saved data to another device first. Then use Disk Management to delete all existing partitions. Then continue with the following steps to initialize the drive.

Step 1. Open Disk Management.

Step 2. Right-click the not initialized HDD/SSD and select "Initialize Disk".

Step 3. Select the disk to initialize in the dialog box and set the disk partition style as MBR or GPT.

3. Will initializing a disk erase it?

Solely initializing a disk won't erase its data. But in order to use the disk, you need to further partition and format the disk, which will cause data loss.

Thus, if you don't want to lose files existing on your hard drive, using data recovery software is necessary. You may refer to Recover Data from Unknown Not Initialized Hard Drive for a detailed guide. 

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Updated by Tracy King

Tracy is enthusiastic to share technical tips and solutions about computing and technology. Being an EaseUS member since 2013, she also writes instructional content about data recovery, file/disk partition/system backup and recovery, partition management and iOS/Android data recovery.

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Written by Roxanne

Roxanne is one of the main contributors to EaseUS and has created multiple posts on digital devices like PCs, Mobile phones, tablets, Mac, etc. She loves to share ideas with people of the same interest.

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