How to Recover Accidentally Deleted Operating System in Windows 10

Jean updated on Nov 20, 2020 to Partition Master | How-to Articles

Accidentally Deleted Operating System in Windows 10

It's not easy to delete Windows operating system during our daily use and impossible to delete it if you are operating in Windows. However, the Windows operating system is not undeletable. Generally, there are several situations in which you may accidentally delete the operating system on your computer.

  • Accidentally delete OS in Windows Preinstallation Environment
  • Boot a computer via a bootable media and then delete the operating system by mistake
  • The computer has dual operating systems and you delete one of them after booting into another
  • You delete the operating system after system clone, OS reinstallation, system recovery, misoperation...

When the operating system is deleted, you can't boot your computer as expected and the files stored on your computer hard drive are inaccessible. To eliminate this annoying issue, you need to recover the deleted operating system and make your computer boot normally again. 

How to Recover Accidentally Deleted Operating System in Windows 10

Generally, deleting an operating system means deleting the whole system partition. Thus, you need a partition tool - EaseUS Partition Master to recover the deleted system partition. With the help of this tool, you can recover your deleted operating system in Windows 10 and boot your PC normally again via three procedures:

  • Create a bootable media with EaseUS Partition Master
  • Boot your computer from the bootable media and recover the system partition.
  • Afterward, you can add a boot option in BIOS/UEFI to boot Windows from your computer hard drive again. To get back your deleted OS:
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 Windows 10 is supported


Step 1: Prepare a disc or drive

To create a bootable disk of EaseUS Partition Master, you should prepare a storage media, like a USB drive, flash drive or a CD/DVD disc. Correctly connect the drive to your computer.

Launch EaseUS Partition Master, go to the "WinPE Creator" feature on the top. Click on it.

create easeus partition master bootable disk

Step 2: Create EaseUS Partition Master bootable drive

You can choose the USB or CD/DVD when the drive is available. However, if you do not have a storage device at hand, you can also save the ISO file to a local drive, and later burn it to a storage media. Once made the option, click "Proceed".

create easeus partition master bootable disk

You have created an EaseUS Partition Master WinPE bootable disk now. You can manage your hard disks and partitions through the bootable drive whenever the computer fails to boot normally.

If you have RAID drives, load the RAID driver first by clicking Add Driver from the menu bar, which can help you add the driver of your device under WinPE environment, as some specific device cannot be recognized under WinPE environment without drivers installed, such as RAID or some specific hard disk.

Procedure 1. Create a Bootable Media with EaseUS Partition Master

You have created an EaseUS Partition Master WinPE bootable disk now. Connect the WinPE bootable disk you have made to the PC with the corrupted Windows system, restart the computer and go to BIOS/UEFI to change the boot sequence. Press "F2" (the BIOS key varies according to the computer manufacturer) when you start your PC. It will allow you to run EaseUS Partition Master and recover your system partition without Windows.

Before you start, there are things you need to identify.

If you see your original system partition shown as unallocated space in EaseUS Partition Master or RAW, you can recover the partition and the Windows operating system together with it following the steps below. If you see the system partition still exists but you cannot boot your computer. It's probably some Windows system files are deleted by mistake. In such a case, you can refer to the article about system boot issues (this article is related to other software but some of the solutions are universal) or create a bootable media with the hard drive recovery software - EaseUS Data Recovery Wizard, boot your computer from the device, recover your deleted Windows system files, and create a boot option in BIOS/UEFI to recover your operating system.

Procedure 2. Recover Deleted Operating System in Windows


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 or recently deleted partition at a fast speed.
  • Deep Scan will scan and find more and earlier deleted partitions. 
  • If the Quick Scan doesn't find your lost partition, wait patiently till the Deep Scan completes.
Scan lost partitions

During or after the scan, you can double-click the partition marked as "Deleted" to check and view the partition content. If it contains your lost partition data, go to Step 4 and continue. 

Check lost partition contents

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
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 Windows 10 is supported

Procedure 3. Add a Boot Option

Adding a boot option in BIOS or UEFI boot mode is not easy to do. You can search for the guide on the Internet according to your boot mode and brand of your computer. Or you can directly contact our support team via live chat or telephone number provided below for remote assistance. In addition to creating the boot option, our support team can also help in other aspects like data recovery.

Do You Need Specialized Services for System Boot Issues?
EaseUS also provides 1-on-1 remote assistance to fix the boot issue. If the solution above does not work for you, please contact our professionals via Email or LiveChat in this page. To ensure our professional assistance work, you are suggested to connect the unbootable system drive to a healthy computer when getting connected with us.

The Bottom Line

Accidentally deleting operating system is quite rare but still exists. To reaccess the files on your computer and recover the deleted OS, you need to create a bootable media with partition recovery software, like EaseUS Partition Master, which is 100% secure, virus-free, and plug-in free. If you have any difficulty performing data recovery or adding a boot option, you are welcomed to ask help from our support team.

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Frequently Asked Questions

Why Choose EaseUS Partition Master?

"I've used Partition Master Professional many times to create, delete, format, move, rename, and resize partitions."PCWorld

"Partitioning tools have come a very long since the days of complicated command line utilities and EASEUS Partition Master is one of the most advanced programs available."TECH ADVISOR

"I love that the changes you make with EaseUS Partition Master Free aren't immediately applied to the disks. It makes it way easier to play out what will happen after you've made all the changes."Lifewire

Will the "Migrate OS" feature transfer the Windows system files only or the whole C drive?

To ensure that the migrated system will boot normally, the Migrate OS feature will transfer all the files in the system and the boot partitions. Generally, the boot partition is the C drive so the transfer will include all the files in C.

Does EaseUS Partition Master license apply to multiple computers?

The license of Partition Master Professional and Server editions can be used on 1 computer only, while that for for the Technician and Unlimited editions can be used on multiple machines.

What is the difference between EaseUS Partition Master Trial version and the Free version?

Free is for home users only, with most basic functions available such as partition resize and clone. While trial can help you understand how this product works and test what a full license can do on a business or server OS machine.

Will it cause any data loss after resizing the partition in EaseUS Partition Master?

Generally, it will not cause any data loss or boot issue by resizing a partition. However, in order to protect your data, we suggest that you backup the partition before resizing, in case of any unexpected situations such as power outages, computer hardware failures, etc. You can use EaseUS Todo Backup to backup the partition and its trial version is fully functioned for 30 days.

What should I prepare before resizing the partition?

On the partition that is going to be operated, there might be some files being occupied by other programs. To ensure a successful operation, we suggest that you close all the unnecessary software before resizing that partition. Otherwise, EaseUS Partition Master will detect the partition being locked by the other software and require a reboot to resize the partition under boot mode.

About EaseUS Partition Master

All-round disk & partition management software for personal and commercial use. Let it manage your storage drive: resize, format, delete, clone, convert, etc.

Video Tutorial

How to Partititon a Hard Drive on Windows 10/8/7