How to Recover a Lost Partition After Windows Update (GPT/MBR)

Introduction

To recover lost partition after windows update, you need to act quickly and understand how Windows updates affect disk structures.

A lost partition after windows update often occurs when the update modifies the partition table, converts between GPT and MBR, or introduces driver conflicts that hide the partition.

This guide provides proven methods to restore your missing partition, recover data, and prevent future loss—whether you use GPT or MBR.

For official guidance, Microsoft’s documentation explains how to manage disks and partitions using Disk Management.

Additionally, the Diskpart command-line utility offers powerful recovery options.

This article builds on those authoritative sources to deliver a complete step‑by‑step recovery plan.

For broader Windows troubleshooting, explore our Windows 11 troubleshooting hub which covers system‑level issues that may affect disk operations.

Why Partitions Disappear After Windows Updates

Understanding the underlying reasons helps you choose the right recovery method.

A lost partition after windows update typically results from one of several causes. Windows updates sometimes modify the partition table to accommodate new system files, which can corrupt existing entries.

If you have a dual‑boot system, an update might overwrite the boot manager, making partitions invisible. Driver updates for storage controllers can change how the disk is addressed, causing the system to misinterpret the partition layout.

In some cases, an update may initiate a conversion between GPT and MBR without proper migration, leading to data loss. Power interruptions during the update process are another common culprit, as they leave the partition table in an inconsistent state.

Corrupted system files or registry entries related to disk management can also prevent partitions from mounting.

Never assume your data is permanently gone. The partition table entries are often recoverable, and the actual data remains intact until overwritten.

Check Disk Management for Unallocated Space

The first step to recover lost partition after windows update is to verify its status in Disk Management. Often, the partition is still present but appears as unallocated space.

1. Press Win + R, type diskmgmt.msc, and press Enter.
2. Look for your disk in the list. If you see a large block of Unallocated space, that may be your lost partition.
3. Right‑click the unallocated space and select New Simple Volume to attempt recovery (but do not format if you want to preserve data).
4. Alternatively, check if the partition appears with a drive letter but is not accessible in File Explorer.

If the partition is visible but shows as RAW or has no file system, proceed to Method 4 (CHKDSK) or Method 5 (TestDisk).

Use Diskpart to Recover the Lost Partition

Diskpart is a powerful command‑line tool that can often recover lost partition after windows update by reassigning the partition ID or making it active.

1. Open Command Prompt as Administrator (search for cmd, right‑click, select Run as administrator).
2. Type diskpart and press Enter.
3. Type list disk to see all disks.
4. Type select disk X (replace X with the disk number containing the lost partition).
5. Type list volume to view all volumes on that disk.
6. If you see the lost partition listed but without a drive letter, type select volume Y (replace Y with the volume number).
7. Type assign letter=Z (replace Z with an available drive letter).

If the partition is not listed, you may need to use the detail disk command to inspect the partition table. For GPT disks, you can also use gpt attributes to check hidden partitions.

Assign a Drive Letter to the Missing Partition

Sometimes a lost partition after windows update is simply hidden due to a missing drive letter. This method restores access without altering data.

1. Open Disk Management (diskmgmt.msc).
2. Locate the partition that appears without a drive letter.
3. Right‑click it and select Change Drive Letter and Paths.
4. Click Add and assign a new drive letter.
5. Click OK and check File Explorer for the restored partition.

If the partition does not appear at all, try rescanning disks in Disk Management (Action → Rescan Disks) to refresh the view.

Run CHKDSK to Repair File System Errors

File system corruption can prevent a partition from mounting. CHKDSK can recover lost partition after windows update by fixing logical errors.

1. Open Command Prompt as Administrator.
2. Type chkdsk X: /f (replace X with the drive letter of the lost partition, if it has one).
3. If the partition is RAW or has no letter, use chkdsk X: /f with the volume path (e.g., \\?\Volume{GUID}).
4. Press Enter and wait for the scan to complete.
5. After repair, restart your computer and check if the partition is accessible.

Note: CHKDSK works best on NTFS and FAT32 file systems. For exFAT or other formats, use chkdsk /f /r for a more thorough scan.

Use TestDisk to Rebuild the Partition Table

TestDisk is a free, open‑source tool designed specifically to recover lost partition after windows update by rebuilding the partition table.

1. Download TestDisk from the official website and extract the files.
2. Run testdisk_win.exe as Administrator.
3. Select the disk containing the lost partition and choose Proceed.
4. Select the partition table type (Intel for MBR, EFI GPT for GPT).
5. Choose Analyse to search for lost partitions.
6. Select Quick Search to find deleted partitions.
7. If found, highlight the partition and press P to list files (to verify).
8. Press Enter to confirm the partition structure and write the new partition table.

TestDisk is highly effective for both GPT and MBR disks. Always create a disk image before writing changes if you are unsure.

Recover with Third‑Party Partition Recovery Software

When built‑in tools fail, third‑party software can recover lost partition after windows update with a graphical interface and advanced scanning.

1. Download a reputable tool like EaseUS Partition Recovery, MiniTool Partition Wizard, or Stellar Data Recovery.
2. Install and launch the software.
3. Select the disk with the lost partition and choose Partition Recovery.
4. Let the tool scan the disk (this may take 10–30 minutes).
5. Preview found partitions and select the one you want to recover.
6. Follow the prompts to restore the partition and its data.

Always use trusted tools and avoid freeware with questionable permissions. Some tools offer trial versions that allow previewing data before purchase.

Restore from a System Restore Point or Backup

If you created a system restore point or full backup before the update, you can recover lost partition after windows update by rolling back system changes.

1. Open Control Panel → Recovery → Open System Restore.
2. Select a restore point created before the problematic update.
3. Click Next and follow the wizard to restore system files and settings.
4. After reboot, check if the partition reappears.

If you have a full disk image backup (e.g., using Macrium Reflect or Windows Backup), restore the entire disk to a previous state. This is the most reliable way to recover both partition structure and data.

Rebuild the BCD (Boot Configuration Data)

For partitions that contain boot files, rebuilding the BCD can recover lost partition after windows update by fixing boot‑related issues.

1. Boot from a Windows installation USB or recovery drive.
2. Select Repair your computer → Troubleshoot → Command Prompt.
3. Type bootrec /fixmbr and press Enter.
4. Type bootrec /fixboot and press Enter.
5. Type bootrec /scanos to detect Windows installations.
6. Type bootrec /rebuildbcd to rebuild the boot configuration data.

After running these commands, restart your PC. If the partition was hidden due to boot configuration errors, it should now appear in Disk Management.

Convert MBR to GPT or Vice Versa (If Needed)

Sometimes a Windows update changes the disk format (MBR to GPT or vice versa) without warning, causing partitions to become inaccessible. You may need to recover lost partition after windows update by converting back or repairing the partition style.

1. Open Command Prompt as Administrator.
2. Type diskpart and then list disk.
3. Identify the disk with the lost partition and note its partition style (GPT or MBR).
4. If you need to convert MBR to GPT without data loss, use mbr2gpt /validate followed by mbr2gpt /convert.
5. For GPT to MBR, you must use third‑party tools like MiniTool Partition Wizard that support conversion without data loss.

Warning: Converting partition styles carries a risk of data loss. Always back up critical data before proceeding.

Prevent Future Partition Loss with Regular Backups

The best way to avoid a lost partition after windows update is to maintain regular backups and system images.

1. Enable System Protection for your system drive to create automatic restore points.
2. Use File History or Windows Backup to back up personal files regularly.
3. Create a full disk image using Macrium Reflect or EaseUS Todo Backup.
4. Store backups on an external drive or cloud storage.
5. Test your backups periodically to ensure they are restorable.

For comprehensive system protection, explore our backup guide (although for Windows, we recommend similar principles).

Advanced Technical Fixes

For expert users, these advanced methods go beyond standard recovery procedures.

Hex Editing the Partition Table

Using a hex editor like HxD, you can manually inspect and repair the partition table entries. This requires deep knowledge of the GPT header or MBR structure (sector 0 for MBR, sector 1 for GPT). Only attempt this if you have a full disk backup.

Recovering from the Windows.old Folder

After a feature update, Windows often creates a Windows.old folder. If the update caused partition loss, you may find your old system files there. Use File Explorer to navigate to C:\Windows.old and extract any needed data.

Using WinPE to Mount and Repair Partitions

Boot into Windows Preinstallation Environment (WinPE) from a recovery drive. Use diskpart to set the partition as active, then use bcdboot to rebuild the boot files. This often recovers partitions that are invisible in normal boot mode.

For additional Windows recovery techniques, see our guide on fixing Windows 11 BSOD which includes partition‑related error codes.

Conclusion

Recover lost partition after windows update is achievable with the right tools and systematic approach. Start with Disk Management and Diskpart (Methods 1‑3), then progress to TestDisk or third‑party software if needed.

The success of each method depends on whether the partition table was corrupted or the data was physically overwritten. Typically, quick action (within a few hours) yields the highest success rate.

If you encounter persistent issues, consider professional data recovery services. Above all, implement a regular backup strategy to avoid future partition loss.

Your data is irreplaceable—protect it with system images and file backups.

For additional Windows support, explore our Windows 11 troubleshooting hub to address other update‑related problems.

Related Guides

• Windows 11 Troubleshooting Hub
• Fix Windows 11 Update Stuck
• Fix Windows 11 Blue Screen of Death
• External Hard Drive Not Showing in Windows 11
• Fix Windows 11 Disk Usage 100%
• Fix Windows 11 File Explorer Not Responding
• Fix Windows 11 Running Slow
• Recover Deleted Photos from Windows 11

Frequently Asked Questions

How can I recover lost partition after windows update without third‑party software?

Use Disk Management to check for unallocated space, assign a drive letter, or run chkdsk and diskpart commands. These built‑in tools often resolve the issue without external software.

Can I recover lost partition after windows update if the disk shows as RAW?

Yes. Use chkdsk X: /f to attempt repair, or use TestDisk to rebuild the partition table. If RAW persists, third‑party recovery tools like EaseUS can recover files from RAW partitions.

Will recovering a lost partition after windows update delete my data?

Most recovery methods (assigning drive letters, using TestDisk, or running CHKDSK) do not delete data. However, reformatting or writing a new partition table without proper verification can cause data loss. Always back up critical data first.

How long does it take to recover lost partition after windows update with TestDisk?

A quick search takes 2–5 minutes, while a deeper search can take 15–30 minutes depending on disk size and speed. The process is non‑destructive.

What’s the difference between GPT and MBR in partition recovery?

GPT supports larger disks (over 2TB) and more partitions, and it stores multiple copies of the partition table for redundancy. MBR is older and uses a single partition table. Recovery methods differ slightly; TestDisk lets you choose the correct type for your disk.

Can a Windows update permanently delete a partition?

Permanent deletion is rare. The update typically corrupts the partition table entry or changes the partition type, but the data remains until overwritten. With timely recovery, you can almost always retrieve the partition.

How do I prevent lost partition after windows update in the future?

Create a system restore point before major updates, use backup software to create disk images, and ensure your disk has sufficient free space. Also, avoid interrupting the update process.

Is it safe to use third‑party recovery tools for lost partition after windows update?

Yes, if you use reputable tools like EaseUS, MiniTool, or Stellar. Always download from official websites and read user reviews. Avoid unknown or freeware tools that may contain malware.

What should I do if none of the recovery methods work?

If built‑in tools and third‑party software fail, your partition may be physically damaged or overwritten. In that case, consider sending the disk to a professional data recovery service.

Can I recover lost partition after windows update using System Restore?

System Restore can revert system settings but does not directly recover partitions. However, if the partition was hidden due to a system configuration change, a restore point may fix it. For partition table issues, use TestDisk instead.

Editorial Team