Deleting a partition during Windows installation does not immediately erase the files on it — Windows removes the partition table entry, while the underlying data blocks remain until overwritten. This guide explains how to recover a partition accidentally deleted in Windows Setup, organized by three real-world scenarios
Stop immediately if you accidentally deleted partition in Windows setup. Do not create a new partition, format, or continue installing Windows on that unallocated space. Deleting a partition in Windows Setup only removes the partition table entries; your files are usually still on the disk and aren't immediately erased.
You're staring at the Windows installation screen. You clicked "Delete" on a partition—maybe thinking it was the right one, maybe just trying to clean things up—and now it's gone. The space shows as "Unallocated", and your files are no longer visible. Your stomach drops.
Here's the single most important thing to understand before you do anything else: the data is probably still physically on the drive. When you delete a partition in Windows Setup, Windows doesn't immediately scrub the files. It removes the partition table entry—the "map" that tells the system where those files live. The actual data blocks remain until something new is written over them.
That means recovery is often possible. But the steps you take in the next few minutes determine whether it stays possible.
This guide covers exactly what to do (and what absolutely not to do) when you've accidentally deleted a partition during Windows installation, including the scenario where you've already clicked "Next" and let Windows create a new partition on that space.
Before any recovery method, you must prevent Windows Setup (or any subsequent installation) from writing new data onto the affected drive.
If you are still on the Windows Setup partition screen:
If you have already proceeded with the installation on a different disk (for example, you installed Windows onto a separate SSD but accidentally deleted a data HDD), the situation is less urgent. But you still need to avoid saving new files, installing software, or letting Windows index that drive until you attempt recovery.
This is the best-case scenario. The partition is gone, but nothing has been written to the unallocated space.
MyRecover includes a dedicated Partition Recovery wizard designed exactly for this situation—restoring the partition entry itself, not just extracting individual files. It is a practical option when you are working from a bootable environment or have connected the affected disk to a working Windows computer as a secondary drive.
Prerequisites before you start:
Step-by-step process to recover a deleted partition in Windows 11/10 with MyRecover:
1. Run MyRecover. Open MyRecover on the working Windows computer after installing.
2. Launch Partition Recovery. Click Partition Recovery under the Advanced Recovery section on the left. From the disk list, select the physical disk that contained the lost partition. Verify the disk by its number, capacity, and model—this prevents you from scanning the wrong drive.
3. Choose a scan mode. MyRecover offers two modes:
4. Review the scan results carefully. After the scan completes, MyRecover lists the partitions it found, showing the partition name, file system (e.g., NTFS, FAT32), capacity, start/end sectors, and flag (Primary/Logical). Compare the capacity and sector boundaries against what you remember about the lost partition.
5. Select and recover. Check the box next to the correct partition and click Proceed. MyRecover will rewrite the partition table entry. Once complete, the partition should reappear in Windows Explorer with its original drive letter and folder structure intact.
Don't use Windows Setup's "Repair your computer" option expecting it to restore a deleted data partition. Startup Repair is designed for boot issues, not partition table reconstruction.
Don't run bootrec commands. They won't help with a missing data partition and may alter boot records unnecessarily.
This is the panic scenario: you deleted the partition that held your existing Windows installation, and now the machine has no operating system.
If you deleted the system partition and then proceeded to install Windows onto that same unallocated space, the installation process has already written new files over the old ones. In that case, recovering the previous Windows installation is effectively impossible. Microsoft support is blunt about this: once the Media Creation Tool or Windows Setup has formatted or written to the partition, the old data is not recoverable through normal means.
But here's what you can do:
If you have not yet installed anything new on that unallocated space, the old partition's data may still be intact. Boot from a recovery USB (or connect the disk to another PC) and run MyRecover's Partition Recovery wizard as described above. If the tool can find the old partition boundaries, it can restore the partition entry, and your old files may become accessible again—provided the boot files (EFI system partition) were also recovered or remain intact.
If you have already installed a fresh Windows on that space, your only path to the old data is file-level recovery from the newly overwritten partition. This is significantly less successful because the new installation has claimed the space. Stop using the machine, connect the drive to another computer as a secondary disk, and use MyRecover's Disk Data Recovery or Partition Lost Recovery to scan for file signatures rather than partition structures. Success rates vary wildly depending on how much of the new Windows installation overwrote the old data.
This is more common than people admit. You had two drives: one for Windows, one for data. During the clean install, you deleted partitions on both drives because the setup screen lists all connected disks without always making the distinction obvious.
If you installed Windows onto the correct drive and left the other drive's unallocated space alone, the data on the second drive is likely still fully recoverable. Microsoft community responses to this exact situation recommend installing Windows on the primary disk first, then using data recovery software from within the working Windows environment to scan the second disk.
1. Disconnect the affected data drive before completing the Windows installation. This prevents Windows from automatically initializing or writing to it.
2. Complete the Windows installation on the primary drive.
3. Reconnect the data drive.
4. Do not format it when Windows prompts you that "a disk needs to be formatted before it can be used". That prompt is a death sentence for your data.
5. Install MyRecover (or a comparable tool) on the working Windows system. Use Partition Recovery to restore the deleted partition entry directly. If Partition Recovery does not find the original structure, use Partition Lost Recovery to scan the unallocated space for files and extract them to a third drive.
Two habits eliminate this risk:
As soon as you realize the partition is gone, stop writing to that disk. Everything else—the tool you choose, the recovery method, the success rate—depends on that one rule. Besides, you can also recover files from an unbootable computer, recover files from a corrupted SD card, etc., with MyRecover.