How to Recover Lost or Deleted Partitions on Windows?

Finding out that an entire partition has vanished from your Windows PC can be quite alarming, especially if it contained important documents, photos, or work-related files. This can happen for several reasons. Sometimes, a partition still exists, but you’re not able to access it because of a missing drive letter, partition table corruption, or even a configuration setting preventing Windows from recognizing it.

Other times, the partition may simply be deleted. A lost partition still exists on the drive but is inaccessible, usually because of a missing drive letter, table corruption, or a file-system issue. On the other hand, a deleted partition has been removed from the partition table and shows as unallocated space. Both are usually recoverable, but which one you’re dealing with determines which recovery method applies to you.

This guide will explain what happens when a partition is lost or deleted, when recovery is possible, and walk you through the most effective methods to restore your partition and retrieve your data on Windows.

Before You Do Anything Else

The chances of partition recovery depend on what you do right after the partition goes missing. To maximize the chances of recovering both the partition and its data:

• Do not write new data to the affected drive as it can overwrite the deleted partitions’ metadata or files.
• Don’t format the drive or unallocated space because it may permanently delete the underlying data.
• Do not try to rebuild the partition table unless you know what you’re doing.
• Avoid downloading unknown repair utilities from unverified sources.

When Does a Partition Get Lost or Deleted?

A partition can become inaccessible or disappear for many reasons, some of the usual suspects are:

Partitioning Errors: All actions related to creating, resizing, merging, or deleting partitions bear certain risks. A misstep or an unreliable partition management tool can render the partition inaccessible or even delete it completely.

Accidental Deletion: Deleting the wrong partition seems impossible, yet it happens quite often due to various drives or volumes sharing similar names. You may accidentally lose the entire partition in Disk Management or other partitioning tools.

Power Loss During Partition Operation: A sudden loss of power during creation, resizing, or modification of a partition can corrupt the partition structure and make it disappear.

Damaged Partition Table: The partition table contains information about the drive partitions. Software glitches, improper shutdowns, or physical disk problems can damage this table, which stops Windows from recognizing one or more partitions.

Windows Update Problems: At times, significant OS upgrades disk configuration or bring up other partition-related issues. For example, users report missing partitions after applying feature updates or installing a new Windows version.

Hardware Failures: Over time, a storage device wears out and becomes vulnerable to various hardware problems. Physical damage, overheating, or manufacturing defects can make the partition inaccessible.

Malware Attack: Some forms of malware attack the storage drive by corrupting partitions, or by altering the partition table or file system in such a way that accessing the data becomes impossible.

Drive Firmware Problem: Drive firmware bugs sometimes affect the partitioning of the storage device. While manufacturers provide firmware updates to fix the problem, some drives with older firmware may still be at risk of losing partitions.

RAW Partition: Sometimes, the partition is still visible in File Explorer with its drive letter intact but Windows reports its file system as RAW instead of NTFS or FAT32 and prompts you to format the drive before you can open it. This usually means the file system metadata is corrupted or unreadable.

BitLocker Encryption Issues: If the affected drive is BitLocker-encrypted, a damaged partition can also mean a damaged encrypted volume header. Windows’ repair-bde command can salvage readable sectors from a corrupted BitLocker volume before you try the methods below.

Does SSD TRIM Affect Partition Recovery?

It can, particularly when the deleted partition is stored on an SSD drive. Unlike conventional HDDs, the vast majority of current SSD drives are equipped with the TRIM function which allows maintaining the performance level by deleting blocks of data that are no longer used.

Deleting a partition in Windows results in marking the space occupied by the partition as unallocated. In case of an HDD drive, the data will be stored on the disk until it gets erased, so that it will be easy for a partition recovery program to restore it. With an SSD drive having the TRIM function, though, the system might ask the drive to erase unused blocks.

Recovery odds drop sharply once you reach this point. Before attempting any repair on an SSD, create a full sector-by-sector image of the drive with Stellar Data Recovery Professional’s disk imaging tool and run recovery on the image instead of the original disk.

To check whether TRIM is actually enabled on your system:

• Open Command Prompt as administrator.
• Run the following command:

fsutil behavior query DisableDeleteNotify

• A result of 0 means TRIM is active.
• A result of 1 means it’s disabled.

NVMe drives use a similar Deallocate command instead of TRIM, with the same effect on deleted data. If you’re recovering from an external drive through a USB-SATA bridge, note that many bridges don’t pass TRIM/UNMAP commands through at all, which can work in your favor.

Methods to Recover Lost or Deleted Partitions in Windows

The methods below include recovery through Disk Management, a Windows built-in utility, and professional partition recovery software. Understand the scenarios and follow the steps carefully to regain access to your partition and its data.

These methods aren’t meant to be run in numerical order, each one targets a different symptom. Recover your files first with a recovery tool, and only run disk-repair commands like CHKDSK afterward, since repair operations can write to the drive and reduce what’s recoverable.

1.      Assign a Drive Letter to a Partition Missing from File Explorer

Each partition on your storage devices needs a drive letter in Windows to show up in File Explorer. Even if all your data is still intact, a partition without a letter won’t appear. If its original letter was removed, the quickest solution is to assign a new one.  Disk Management is Windows’ built-in tool for viewing and managing drives and partitions, and it’s where you’ll do this.

• Press Win + X and click Disk Management.

• Right-click on the partition which is missing the drive letter and click Change Drive Letter and Paths.

• Click Add.

• Select a drive letter, then click OK.

Once you have assigned a drive letter, you will be able to access the partition once again using File Explorer.

Note: Formatting a partition with data will cause you to lose your files. If that happens, you must stop using the drive immediately and use professional data recovery software to recover data from formatted drives or partitions.

2.      Recover Your Lost Partition Data

If the partition doesn’t show up in Disk Management at all, not even as unallocated space, it’s likely been removed from the partition table. You’ll need a dedicated partition recovery software – Stellar Data Recovery Professional instead. It scans the raw disk sectors for the deleted partition’s file signatures and restores files under their original names and folder structure, even without a partition entry to read from.

If the affected drive is your system disk and Windows won’t boot because of it, you can create a bootable USB using the Recover Non Boot PC option from the sidebar. You can then use this USB recovery to start the PC and recover your data.

• Download and launch Stellar Data Recovery Professional on a different drive than the one you’re recovering from.
• On the What to Recover screen, select the type of data you want to recover and click Next.

• On the Recover from screen, select the Can’t Find Drive option and click Scan.

• Select the physical disk that you want to scan for lost partitions and click Search.

• Once the search is complete, the recovered partitions are displayed in the Select Partition window.

• Select the partition you want to recover and click Scan.

• The recovered files are displayed for you to Preview.

• Select the files you want to retrieve and click Recover.
• The files will be saved to your desired location.

3.      Scan the Partition Using CHKDSK

CHKDSK scans a partition for file system errors and fixes logical issues that prevent Windows from accessing it. There is, however, one catch. CHKDSK only works if the partition is still detected by Windows and has a drive letter assigned. It cannot recover a deleted partition or rebuild a damaged partition table.

Note: The /f switch writes to the drive to repair it, which can push orphaned data into a found.000 folder and rewrite metadata. Recover your files first, and only run CHKDSK once that’s done.

• Open the Command Prompt as administrator.
• Run the following command (replace Z with the drive letter of the affected partition and press Enter):

chkdsk Z: /f

• Wait for the scan and the repair process to finish.
• Restart your PC and check if the partition is accessible.

4.      Use TestDisk to Recover Lost Partition

TestDisk is an open-source application for recovering lost partitions. Since it doesn’t require installation, you can simply extract the downloadable archive and run the executable.

Caution: TestDisk is a technical tool meant for advanced users who are comfortable using the command line interface. Choosing the wrong option can cause further damage to the disk and cause permanent data loss.

• Download and launch TestDisk on your PC.
• Run testdisk_win.exe as administrator.
• Choose whether you want TestDisk to generate a log file.
• Highlight the disk with the missing partition.
• Select the partition table type or let TestDisk detect it automatically. Choose EFI GPT for GPT disks or Intel for MBR disks.
• Scan the drive.
• Select the found partition and save the new partition table.
• Reboot for the changes to take effect.

Safer alternative: if you only need your files back and don’t need the partition itself restored, use TestDisk’s Advanced menu to copy files off the drive directly, without writing a new partition table. This avoids the risk of an incorrect write and keeps the original disk untouched.

5.      Recreate the Deleted Partition Using Disk Management

When the above methods fail to restore the missing partition and you’ve already recovered your important files – the remaining option is to create a new partition. It will initialize the unallocated space with a new file system and replace the damaged or deleted partition structure. It won’t recover the original partition but will make the disk space usable again.

• Press Win + X and click Disk Management.
• Right-click the unallocated space and select New Simple Volume.

• Click Next.

• Specify how large you want the volume to be. Click Next.

• Assign a drive letter and click Next.

• Select file system as NTFS and perform a Quick format.

• Click Finish.

Summing Up

Recovering a lost or deleted partition is possible but preventing partition loss in the first place is always the better approach. Some simple steps can minimize the risk of permanent data loss. Once you notice that a partition has disappeared – stop using the affected drive immediately to avoid overwriting recoverable data. Be cautious when working with disk management or partitioning tools and don’t click an option unless, you’re sure. Likewise, only use trusted software that requires low-level access to your storage devices because unreliable utilities can damage partitions or make recovery more difficult.

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