[Fixed] Unable to Reset Your PC. A Required Drive Partition Is Missing

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Jean updated on Aug 13, 2021 to Computer Instruction | How-to Articles

On this page, we'll explain what causes Windows unable to reset your PC, and how to fix this issue without losing any data, and enable you to reset your PC successfully.

Follow the effective solutions here to fix the "Cannot reset PC" error  to unlock the drive to reset your computer without losing any data:

Applies to: Fix "Unable to Reset Your PC" error in Windows 10/8.1/8/7, etc. without losing any data. 

Error: Unable to Reset Your PC

"I'm trying to reset my PC, but when I do it using a USB drive, made with the media creation tool, I get the error: Unable to Reset PC. A required drive partition is missing."

Error: Unable to reset your PC. A required drive partition is missing.

Don't worry if you happen to encounter this issue on your computer while trying to reset your PC in Windows 10/8/7. Here below, we'll guide you to learn what causes this issue and then list the respective solutions for each cause, and last, help you successfully reset your PC without losing any data.

Causes of "Unable to Reset Your PC. A Required Drive Partition Is Missing" Error 

Apart from the missing drive partition error, there is another similar and common error that disallows you from resetting the PC, which is "the drive where Windows is installed is locked".

What do these errors suggest? And how do they come? 'A required drive partition is missing' usually prompts when you're trying to perform a system reset or install a fresh version of Windows 10/8/7. This error message may appear due to:

  • The MBR (Master Boot Record) or BCD (Boot Configuration) has corrupted
  • There is something wrong with your computer disks
  • You system files are missing or damaged
  • As the error indicates, a required drive partition is missing

The solutions vary depending on the specific causes. The corresponding fix for each cause has been provided below.

Workable Solutions Step-by-step Troubleshooting
Fix 1. Run Bootrec.exe Insert Windows installation disk (DVD) or a bootable USB drive into your computer...Full steps
Fix 2. Rebuild MBR Run EaseUS partition software > Right-click C drive and select "Rebuild MBR"...Full steps
Fix 3. Run SFC Restart your PC. When your Windows boots up, repeatedly press...Full steps
Fix 4. Set System Partition Active Run PC from installation media, use command line to set system partition as active...Full steps

Part 1. Recover Data from Missing Partition and Back Up Important Files

Applies to: Protect your data from being removed or deleted due to resetting PC.

Important
According to EaseUS data recovery experts, resetting PC may cause unexpected data loss issue and it's not advised to do so.

If you want to reset PC regardless of the fact that you've failed with the 'a required drive partition is missing' error, please make sure that you've followed the two preparation jobs as listed in this part. 

#1. Recover Data from the Missing Partition

To avoid further data loss when you failed to reset Windows 10/8/7, EaseUS data recovery experts suggest that you check which partition is missing on your PC and apply reliable data recovery software to bring back the missing files first.

Here, you may try EaseUS Data Recovery Wizard - your reliable choice for partition data recovery. It will fully scan the missing partition and find all lost data in quick scan and deep scan modes. 

What's more, it enables all Windows uses to recover lost files from the missing partition in only 3 steps:

Step 1. Choose the location where data loss happened, be it a hard disk drive, external disk, USB, or SD card, then click "Scan".

select a location and click scan

Step 2. You can click Filter to display only the file types you want while scanning. Go to "Deleted Files" or "Other Lost Files", find the files you want.

Choose files to recover

Step 3. After choosing the data, click "Recover" and choose a location on another drive to save the files.

Recover lost data

#2. Back Up Important Files Before Resetting PC

As for resetting your PC will delete your files, settings, and apps, except for the apps that came with your computer, it's also recommended that you create a backup of all important data on your computer to an external storage device.

 There are two ways that you can try to back up your computer data:

1. Manually copy and paste files to an external hard drive. (Time-consuming)

2. Back up all data to an external hard drive at one time with reliable file backup software. (Fast & Efficient)

To save your time and energy, we suggest you apply file backup software like EaseUS Todo Backup for help. It's fast in backing up data and taking smaller space on your external hard drive. 

Part 2. Fix "Unable to reset your PC. A required drive partition is missing" Error

Applies to: Fix "Unable to reset your PC. A required drive partition is missing" error in Windows 10/8/7, Windows 10 reset failed, etc.

Here in this part, we've collected * practical solutions to help you get rid of "Unable to reset PC" error based on the listed causes at the beginner of this page:

  1. #1. Run Bootrec Command to Rebuild BCD
  2. #2. Repair Corrupted MBR
  3. #3. Run SFC
  4. #4. Set System Partition as Active
  5. #5. Run CHKDSK
  6. #6. Perform System Restore

If you are not sure about the reasons why the error occurs, you can try the solutions below in order.

Method 1. Run Bootrec.exe

Bootrec, also called bootrec.exe utility, is a tool provided by Microsoft in the Windows Recovery Environment. Bootrec.exe can be used to fix the Master Boot Record (MBR), Boot Sector, Boot Configuration (BCD), and boot.ini.

If it's the corrupt MBR or BCD that caused "Reset PC failed" issue, the solution is to correct the MBR or BCD record with the help of bootrec.

By the way, running bootrec.exe is also helpful in solving the "Windows is loading files" loop. Here are the steps:

Step 1. Insert Windows installation disk (DVD) or a bootable USB drive into your computer.

Step 2. Restart PC and press the "F2/F12/Del" key to bring up the boot menu.

Step 3. Select either the DVD or the USB disk from the boot menu.

Wait for the computer to boot into the Windows Installation or Recovery DVD.

Step 4. Select "Install Windows" from the screen that appears and then select "Repair" your computer.

Step 5. From the repair menu, select "Troubleshoot" > "Advanced Options" > "Command Prompt".

Open Command Prompt to run command line to repair BCD

Step 6. In the command prompt that opens, issue the following command one by one:

bootrec /fixmbr
bootrec /fixboot
attrib C:\Boot\BCD -h -r -s ren
C:\Boot\BCD C:\Boot\BCD.bak
bootrec /rebuildbcd

Method 2. Rebuild MBR

When the MBR is corrupted on a specific partition, Windows may not allow you to reset the computer. To fix this error, you'll need a powerful computer management tool to rebuild the corrupted MBR.

Here, reliable partition manager software - EaseUS Partition Master with its "Rebuild MBR" feature can help.

Step 1. Create a WinPE bootable disk

  • Launch EaseUS Partition Master, click "WinPE Creator" on the toolbar. Select to create the bootable disk on a USB drive. If your computer has a CD/DVD drive, you can also create the bootable disk to CD/DVD.
  • Click "Proceed" to finish the process.
create a bootable disk

Step 2. Boot EaseUS Partition Master Bootable USB

  • Connect the bootable USB or CD/DVD to your PC. 
  • Press F2 or Del when you restart the computer to enter the BIOS screen. Set and boot your computer from "Removable Devices" or "CD-ROM Drive". And then EaseUS Partition Master will run automatically.
rebuild MBR

Step 3. Rebuild MBR

  • Right-click the disk whose MBR is damaged. Choose "Rebuild MBR" to continue.
  • Select the type of MBR with the current operating system. Then, click "OK".
rebuild MBR
  • Click the "Execute Operation" button at the top-left corner and click "Apply" to build the MBR. After that, your computer can boot normally again.
rebuild MBR

Method 3. Run SFC (System File Checker)

The error "Unable to Reset PC. A required drive partition is missing." may also happen due to missing or corrupted system files.

To your relieve, the Windows System File Checker tool is able to repair missing or corrupted system files for you.

Here are the steps to run the tool:

Step 1. Press Windows + X keys, click Search and type cmd in the search box.

Step 2.  Right-click onCommand Prompt and select "Run as Administrator".

Step 3. Type the sfc command to repair the missing or corrupted system files that causing "Unable to reset PC" error and hit Enter: sfc /scannow

Run SFC command to fix unable to reset PC error

Method 4. Set System Partition as Active

Only one partition can be designated as "Active" and that should be your system partition. If you have assigned the active partition wrongly, your PC won't boot and you may encounter the error message saying, "Unable to reset your PC. A required drive partition is missing".

To set your system partition as active, you'll need to boot your PC up from a Windows installation disk fist, then enter Command Prompt and use some command lines to set the system partition as active. Here are these steps:

Step 1. Insert Windows installation disk (DVD) into your PC and restart the computer.

Step 2. Press the "F2/F12/Del" key to enter the BIOS boot menu.

Step 3. Select the Windows installation USB or the DVD as the boot drive from the boot menu.

Step 4. Reboot PC and wait for the computer to boot into the Windows Installation or Recovery DVD.

Step 5. When "Install Windows" screen appears, select "Repair" your computer.

Step 6. From the repair menu, select "Troubleshoot" > "Advanced Options" > "Command Prompt".

Step 7. Type the following command lines and hit Enter each time to fix "Unable to Reset PC" error:

diskpart
list disk
select disk 0 (the disk contains your system partition)
list partition
select partition 0 (the system partition)
active
exit

Method 5. Run CHKDSK

Disk errors can also result in the issue "Unable to Reset PC. A required drive partition is missing." Fortunately, CHKDSK can be used to check and repair your disk errors like file system errors or bad sectors.

According to some users, running CHKDSK to fix corrupted file system may result some file loss. Don't worry if you have encountered the same issue. EaseUS Data Recovery Wizard is able to help.

Here are the steps:

Step 1. Repeat Step 1 to Step 6 (as shown in Method 1 or Method 4) to boot your PC from the installation media.

Step 2. Choose to repair your computer.

Bring up system restore window when unable to reset PC.

Step 4. Click "Troubleshoot" > "Advanced Option" > Select "Command Prompt".

Step 5. Type the command line chkdsk c: /f and hit Enter.

If this don't work, type chkdsk C: /f /x /r and hit Enter. (Replace "c" with the drive letter of the volume you want to check).

Method 6. Perform System Restore

If the above five methods above all failed to fix the error "Unable to Reset PC. A required drive partition is missing.", your last choice is to restore your system to an earlier point. 

To do so, you still need the help of using Windows installation USB or DVD for help:

Step 1. Insert Windows installation USB and resart PC.

Step 2. Enter BIOS and set PC to boot from Windows installation media USB.

Step 3. On Windows Install window, select "Repair your computer".

Step 4. Select "Troubleshoot" > "Advanced Options" > "System Restore".

Step 5. Choose a previous working state (data) to restore to your computer.

Select system restore point

Step 6. Wait until Windows Restores your system. Then restart your computer.

After this, your computer is now running with a previou healthy version of Windows. Everything will work normally, so to the "Reset PC" operation.

Part 3. How to Reset Your PC After Fixing "Unable to Reset PC" Error

If you still want to reset your computer after fixing "Unable to reset your PC. A required partition is missing" error, follow the steps here one by one, you'll successfully reset the computer on your own:

Important: To avoid unecessary data loss due to resetting PC, we suggest you Backup Files Before Factory Reset PC in advance.

Here's how to reset your Laptop/PC in Windows 10/8/7 easily:

Step 1. Right-click Start or Windows icon, select "Settings > "Update & security" > "Recovery" > "Reset this PC" > "Get started".

reset windows 10 step 1

Step 2. Click either "Keep my files" or "Remove everything".

If you didn't back up any data, select "Keep my files" to keep your data files intact.

In either way, all of your settings will return to their defaults and apps will be uninstalled. 

keep my files or remove everything

Step 3. If you chose "Remove everything" in the prior step, select "only the drive where Windows is installed" or "All drives"

factory reset windows 10 step 3

Step 4. Select "Remove files and clean the drive" if you are going to sale the computer. The next user can't recover your erased files.

If you'll conitnue using the computer, choose "Just remove my files."

factory reset windows 10 step 4

Step 5. Click "Reset" when prompted.

Windows will then restart and take 20 minutes or longer time to reset itself.

clcik reset to start the factory reset process

Wait patiently till the whole process completes and your computer successfully restarts. If the computer works fine, you can restore the backup data to a data drive to make use of them again.

Also read: Recover Files After Resetting PC, How to Factory Reset Mac Without Losing Data

The Bottom Line

Sometimes, you may need to reset PC when there are serious issues on your computer. Don't worry if you encountered the error "Unable to Reset PC. A required drive partition is missing" during the setting PC process. To address this issue, we suggest you restore lost data from the missing partition with the help of EaseUS data recovery software.

Then, you can try the 6 practical methods as shown above to fix the problem successfully without losing any data. When you are done with this error, you can continue resetting the computer, making it work normally again. Once again, remember to back up your precious files with free backup software before the operation.

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