How to Initialize Disk without Losing Data (Two Ideas)

If your disk suddenly becomes not initialized, please continue to read below and learn how to initialize disk without losing data. Here are two great ideas to make it.


By Ivy / Updated on April 2, 2024

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The Disk Unknown Not Initialized Error

The “Disk (0, 1, 2...), unknown, not initialized, and unallocated" is a one of common disk error making users frustrating. It will prevent you from access your drive, along with its data. So how to initialize disk without losing data becomes a problem.

Unknown Not Initialized Unallocated

In general, there are two situations you may encounter a “disk unknown not initialized” error.

  • The disk is brand new and does not contain any data. In this case, you can directly initialize disk MBR or GPT without worrying about data loss. It lets you further partition and format the disk for future use.
  • The disk becomes “ Not Initialized” suddenly. In this case, the disk is likely to contain some important data you don’t want to lose. Then how to initialize disk without losing data? You can either recover data from not initialized disk first or try to fix disk unknown not initialized error.

What Does Initializing a Disk Mean?

A brand new disk will not immediately show up in File Explorer unless you initialize it in Disk Management. So what does initializing a disk mean? Does initializing a disk erase data?

Initializing a disk is a process to prepare a new disk for use or fix an old malfunctioning disk, showing “Unknown, Not Initialized”. It is divided into two parts. Windows will first create a partition table to the drive, either MBR or GPT and then format a disk to a recognized file system. Of these, the format process will surely erase your disk data.

Windows Initialize Disk MBR or GPT

During the disk initialization process, you will be asked to select MBR or GPT partition style. Which one is better? To make this decision, you need to know the differences between them.


MBR (Master Boot Record)

GPT(GUID Partition table)

Partition number

Up to 4 primary partitions

Max. 128 primary partitions

Maximum space



System Architecture

32-bit and 64-bit systems

64-bit systems only


Legacy BIOS





Compatible system

Windows only

Windows and MacOS

In sum, MBR is an old partition style developed in the 1980s and compatible well with old systems, such as Windows XP, 2000, NT4, 95/98, etc. It can also be used on all versions of Windows 7, 8, 8.1, and 10. While GPT disk is more suitable for new systems, especially for Windows 11 and Windows Server 2022, and has a faster boot speed.

How to Initialize Disk Without Losing Data

If you are in the second situation and need to initialize a disk, to be sure your data is safe, it’s suggested to recover data from not initialized disk first. The process should be:

  • Recover data from not initialized disk
  • Initialize disk showing not initialized
  • Partition and format initialized disk

Now follow the process below to initialize disk MBR or GPT without losing data.

Part 1: Recover Data from Not Initialized Disk

MyRecover is one of the most powerful data recovery software in Windows 11, 10, 8, 7, etc and Windows Server, which can recover data from health, problematic(eg: disk showing not initialized) or damaged disk. It can be internal or external disk, USB drive, SD card, etc.

  • Has a high success rate and fast speed.
  • Scan the disk quickly and deeply with two advanced scanning methods and find out all the deleted or lost data completely.
  • Recover Word documents, Excel spreadsheets, PowerPoint presentations, photos, audios, videos, emails, webpages, and compressed files and 200+ file types.
  • Handle all-inclusive data loss scenarios, such as deleted, virus infected, formatted, etc.

Step 1: Install and launch the powerful data recovery software - MyRecover on your Windows PC. Hover the mouse over the drive, and click Scan.

Download Software Windows 11/10/8/7/Server
Secure Download

Select Partition To Scan

Step 2: It will run two advanced scanning methods - Quick Scan & Deep Scan automatically and display all the found files on the selected disk. You can filter and preview files in the disk. Here are two methods:

  • Click Filter and select a file type, such as Documents. Then, type file name or file extension in the Search for files or folders box.
  • Expand the Deleted Files, Recycle Bin, or Other Missing Files tab and check the deleted or lost files on the unknown uninitialized disk.

Scan Lost Data

Step 3. Select all the deleted or lost files on the unknown uninitialized disk and click the Recover x files button. You will then be asked to select a location. Please select a new location instead of original location.

Select Deleted Excel Files Click Recover


  • The restore button will display the number of selected files and their full size. You can use it to determine the integrity of the recovered files.
  • Saving the recovered files to original location may cause data corruption or further data loss.
  • You can recover data from not initialized disk for free, up to 500MB in total. To recover all files on it, try advanced editions.

Except for recovering data from uninitialized disk, you can also recover data from RAW disk, recover files from a formatted hard drive, recover files from SSD, etc.

Part 2: Initialize Disk Showing Not Initialized

After recovering data from uninitialized disk, you will not worry about data loss anymore. You can then initialize disk in Disk Management.

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

Step 2. Locate the disk showing "Not Initialized", right-click on it and select "Initialize Disk".


Step 3. In the "Initialize Disk" window, select the MBR or GPT partition style and click "OK" to proceed.

Initialize MBR or GPT

Part 3: Partition and Format the Initialized Disk

Now you come to the final process. Just follow the steps below to create a new partition on this disk.

Step 1. In Disk Management, right-click the unallocated space and choose "New Simple Volume...".


Step 2. It will open a New Simple Volume Wizard. Click "Next".

Step 3. You will be asked to specify capacity, drive letter, and file system. Just do as suggested. Finally, click Next to partition and format disk.


Another Way to Initialize Disk without Data Loss

Except for using data recovery software, you can also choose to fix the “disk unknown not initialized” error and make your drive and data visible. So how to fix this error?

✍ First, you need to get the possible reasons.

This could be outdated or corrupted drivers, virus attacks, bad sectors, lost partitions, file system errors, MBR corruption, etc. However, if the disk shows no size, the reason could be damaged MBR.

✍ Second, fix this error based on the cause. Here we summarize some useful methods in the following:

  • Scan disk for viruses and malware
  • Rebuild MBR
  • Update disk driver
  • ...

For more details, please check the “disk unknown not initialized” error

Initialize Hard Drive Without Losing Data FAQs

Q1: Does initializing a disk erase data?

No, initializing a disk will not erase any data as it only affects the MBR partition table. But initializing disk will not make disk usable and you still need to partition and format disk, which will result in data loss.

Q2: Should I initialize disk MBR or GPT?

The MBR partition style uses Legacy BIOS and support disk capacity up to 2TB. While GPT partition style is new disk layout that supports UEFI firmware and 9.4ZB storage space. So you can select them based on computer firmware and the disk capacity.  

Q3: How do I initialize disk without losing data in Windows 10?

Similarly, if there are any data on the not initialized disk, you need to recover data from it using data recovery software. MyRecover helps to scan any inaccessible disk (eg: disk suddenly becomes not initialized) and recover data on it quickly.


To summarize, initializing a disk itself does not erase data, but its further steps - partition and format will. So the first step to initialize disk without losing data is to recover data using a professional data recovery software like MyRecover.

In addition, you can also try to fix the “disk unknown not initialized” error and make your disk behave normally. You can then access your disk and data on it. Finally, you’d better create a copy of your files on the disk in case this error occurs again. Try free backup software - AOMEI Backupper Standard.

Ivy · Editor
Ivy is an editor of AOMEI Technology, she covers backup & restore,hard disk & partitions management and cloud files transfer and so on for AOMEI. She is an outgoing girl and enjoys helping people find solutions to their problems. She loves traveling, eating, reading and so on. She usually hangs out with friends at her leisure time.