How to Recover Accidentally Deleted Operating System in Windows 11/10

Updated by

Tracy King 

Written by

Jean 

Updated on Mar 28, 2025

Accidentally Deleted Operating System in Windows 11/10

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 11/10

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 11/10 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:

Step 1. 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. Then, correctly connect the drive to your computer.

Step 2. Launch EaseUS Partition Master, and find the "Bootable Media" feature on the left. Click on it.

Step 3. 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 the "Create" button to begin.

• Check the Warning message and click "Yes".

Step 4. When the process finishes, you'll see a pop up window, asking if you want to restart computer from the bootable USB.

• Reboot Now: it means you want to restart the current PC and enter EaseUS Bootable Media to manage your disk partitions without OS.
• Done: it means you don't want to restart the current PC but to use the bootable USB on a new PC.

Note: To use the bootable disk on a new PC, you need to resart the target computer and press F2/F8/Del key to enter BIOS, and set the USB bootable disk as the first boot disk.

Wait patitiently and your computer will automatically boot up from the USB bootable media and enter EaseUS WinPE desktop.

Note: If you accidentally deleted a Windows 11/10 ISO file to the recycle bin, you can also bring the image file back. See also:

How to Recover Deleted Files from Recycle Bin?

Are you looking for a way to perform Recycle Bin recovery? Follow to learn how to recover deleted files from the Recycle Bin immediately.

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. Open EaseUS Partition Master and click "Partition Recovery". Select the target disk with your lost partition and click "New Scan".

Step 2. Wait patiently to let the software execute "Quick Scan" and "Full Scan" operation. It will mark your deleted partition as "lost" as the Status section. Select the lost partition, and click "Recover".

You can also double click on the partition you're looking for to preview its content and click "OK" to confirm.

Step 3. Wait patiently and click "Done" when the partition recovery process completes.

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.

The Bottom Line

Accidentally deleting the 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.