[Resolved] Unable to Delete the Active System Partition on This Disk in Windows

When using Disk Management to delete a partition, you might encounter an error message stating, "Windows cannot delete the active system partition on this disk." Here's a common scenario where this issue typically arises:

If you're also searching for alternative methods to address this issue, this article will present various solutions to resolve the "Windows cannot delete the active system partition on this disk" problem on single or dual-boot systems.

Why Can't Windows Delete the Active System Partition on This Disk?

Before we proceed, we need to understand why Windows is unable to delete the active system partition on this disk.

The active system partition refers to the primary partition that contains the operating system and is designated for booting. According to Wikipedia, it is defined as follows:

Normally, it is not recommended to delete the system partition. This is because doing so may disrupt the normal functioning of the computer and lead to an inability to boot. The active partition is classified as a primary partition, and it is the partition from which the system boots. Consequently, Disk Management will not permit Windows to delete the active system partition.

Solutions for "Windows Cannot Delete the Active System Partition on This Disk"

Although Windows does not permit the deletion of active system partitions, there are two scenarios in which you might still require this action:

1. There's only one system on the PC. To reinstall the new operating system, you'll need to erase the original system first.

There are two operating systems installed on your PC. Consequently, you wish to remove the unnecessary partition or delete the active system partition in order to free up storage space and acquire unallocated space.

Case 1: Delete Active System Partition in Single System In this scenario, you want to delete an active system partition within a single system setup. Here's how you can proceed: 1. **Backup**: Before making any changes, it's crucial to create a backup of your important data. This ensures you have a safety net in case something goes wrong during the deletion process. 2. **Boot into Recovery Mode**: Restart your computer and enter the system's recovery mode. This is usually done by pressing a specific key (like F2, F10, F12, or Shift + Restart) during startup, depending on your system manufacturer. 3. **Access Command Prompt or Terminal**: In the recovery environment, look for a way to access the Command Prompt (Windows) or Terminal (Linux/Mac). This will allow you to execute commands to manipulate partitions. 4. **Identify the Partition**: Use the `diskpart` utility in Windows or `fdisk`, `lsblk`, or `gparted` in Linux to list all available disks and partitions. Identify the partition you want to delete. - **Windows**: ``` diskpart list disk select disk X (Replace X with the disk number) list partition select partition Y (Replace Y with the partition number) ``` - **Linux**: ``` fdisk -l OR lsblk ``` 5. **Delete the Partition**: Once you've identified the correct partition, proceed to delete it. Be cautious as this step is irreversible. - **Windows**: ``` delete partition override ``` - **Linux**: ``` sudo fdisk /dev/sdX (Replace sdX with the disk identifier) Command (m for help): d Partition number (1-4): Y (Replace Y with the partition number) ``` 6. **Confirm Changes**: Save the changes made to the partition table and exit the utility. - **Windows**: ``` exit ``` - **Linux**: ``` Command (m for help): w ``` 7. **Reboot**: After deleting the partition, reboot your system to apply the changes. Remember that deleting an active system partition might render your computer unbootable. If you're planning to reinstall the operating system, ensure you have the necessary installation media ready. If you're removing a secondary system to free up space, make sure you have another valid boot option configured.

For the first scenario, there are three possible solutions:

Solution 1: Use Partition Master Tool

Fix 2. Run the Diskpart Command

Fix 3. Use Windows Installation Disc

Let's examine each step individually to resolve the issue where Windows is unable to delete the active system on the disk.

Solution 1: Utilize Partition Master Tool

You need to enter the Win-PE environment by creating a bootable media to delete system partitions in a single system. I highly recommend using the user-friendly yet powerful disk and partition management tool, tools Partition Master.

Here are the steps to resolve the issue "Windows cannot delete the active system partition on this disk": 1. **Boot into Safe Mode**: Restart your computer and press F8 repeatedly during startup to enter the Advanced Boot Options menu. Choose 'Safe Mode with Networking' to boot into a minimal system environment. 2. **Create a System Repair Disc**: If you don't have one already, create a System Repair Disc or USB using another working Windows PC. This will allow you to access advanced recovery options. 3. **Boot from the Repair Disc**: Insert the disc or USB and restart your computer. Boot from it by changing your BIOS settings to prioritize CD/DVD or USB boot. 4. **Choose 'Repair your computer'**: In the Windows Setup screen, select your language preferences, then click 'Next'. Choose 'Repair your computer' in the lower-left corner and proceed to the System Recovery Options. 5. **System Restore**: In the System Recovery Options, choose 'System Restore' and follow the on-screen instructions to revert your system to a previous point before the issue occurred. 6. **Command Prompt**: If System Restore doesn't work, choose 'Command Prompt' from the System Recovery Options. 7. **Disabling the Active Partition**: Type the following commands one by one, pressing Enter after each: - `diskpart` - `list disk` (Identify the disk where the system partition is located) - `select disk X` (Replace 'X' with the number of the identified disk) - `list partition` (Identify the system partition) - `select partition Y` (Replace 'Y' with the number of the system partition) - `inactive` (This command will make the system partition inactive) 8. **Delete the Partition**: Now, you can try deleting the system partition with the following command: - `delete partition override` 9. **Recreate the Partition**: After deletion, recreate the partition with: - `create partition primary` 10. **Format and Assign Drive Letter**: Format the new partition and assign a drive letter: - `format fs=ntfs quick` (or choose another file system if needed) - `assign` 11. **Exit and Restart**: Exit the Command Prompt and restart your computer. It should now be able to delete the system partition normally. 12. **Reinstall Windows**: If all else fails, you might need to perform a clean installation of Windows. Make sure to back up your important data before proceeding. Remember that these steps involve modifying crucial system components, so exercise caution and ensure you have a backup plan in case something goes wrong.

Guide 1: Create Bootable Media Step 1: Choose the Right Software Select a reliable tool for creating bootable media, such as Rufus, balenaEtcher, or Microsoft's Media Creation Tool, depending on your needs and operating system. Step 2: Download the ISO Image Download the ISO image of the operating system or software you want to install from an official source. Ensure the file is genuine and unaltered. Step 3: Prepare a USB Drive Insert a USB drive with sufficient capacity (usually 8GB or more) into your computer's USB port. Remember that all data on the USB drive will be erased during the process. Step 4: Launch the Bootable Media Creator Open the chosen software, and it should automatically detect the connected USB drive. If not, select the correct drive from the available options. Step 5: Configure Settings In the software, choose the downloaded ISO image as the source and ensure the target device is set to your USB drive. Check any additional settings if needed, like partition scheme, file system, or boot mode (UEFI or BIOS). Step 6: Start the Process Click on "Start," "Create," or a similar button to begin the creation of the bootable media. The process may take several minutes, depending on the speed of your USB drive and computer. Step 7: Verify the Bootable Media Once completed, safely eject the USB drive and insert it into the device where you plan to boot from it. To verify the media, restart the computer and access the boot menu (usually by pressing F2, F10, F12, or Del during startup, depending on the manufacturer). Select the USB drive as the boot device. Step 8: Boot and Install The system should now boot from the USB drive, allowing you to proceed with the installation process or run the software directly. Remember to follow the specific instructions provided by the software you're using, as some steps or options might differ slightly.

You need to create a bootable disk or DVD/CD to enter the operating system. Just follow the steps.

Step 1. To create a bootable disk of tools Partition Master, you'll need a storage medium, such as a USB drive, flash drive, or a CD/DVD disc. Connect it properly to your computer.

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

Step 3. When the drive is available, you can select either USB or CD/DVD. However, if you don't have a storage device on hand, you can also save the ISO file to a local drive and burn it to a storage medium later. After making your choice, click the "Create" button to start the process.

Check the Warning message and click "Yes".

Step 4. When the process is complete, a pop-up window will ask you if you want to restart your computer from the bootable USB.

• Reboot Now: This means you wish to restart the current computer and enter the Bootable Media tool to manage your disk partitions without an operating system.
• Done: This indicates that you do not want to restart the current PC, but instead intend to use the bootable USB drive on a different computer.

Important: To use the bootable disk on a new PC, you need to restart the target computer and press F2/F8/Del keys to enter BIOS, then set the USB bootable disk as the first boot device.

Just hang tight, your computer will automatically boot from the USB boot media and launch into the WinPE desktop tool.

Guide 2: Restart the Computer from the Bootable USB

Step 1. Restart the computer and press "F2," "F8," or "Delete" for an extended period to enter BIOS. (The specific key varies depending on your computer)

Step 2. In the BIOS, boot the computer from the bootable USB drive.

Guide 3: Delete Partition

Then, you will enter the tool page of Partition Master. And you need to click it to start deleting the active system on the disk.

Please note that this action will delete all existing partitions on the system disk, including the operating system. Therefore, ensure you have backed up all important data beforehand.

Step 1. Launch AOMEI Partition Assistant, go to the Partition Manager section, right-click your OS disk and select "Delete All".

Step 2. Click "Yes" to confirm that you want to delete all partitions on the OS disk.

Step 3. Click "Execute * Task" and then click "Apply" to begin deleting all partitions with the operating system on the selected disk.

Note: Now, all you have to do is wait patiently, and Partition Master will automatically delete the OS drive and other data partitions on your disk.

Solution 2: Run the Diskpart Command

Utilizing the Diskpart command is another approach that might work. You can attempt the following steps to delete the active Windows partition: 1. Press the 'Windows key + X' on your keyboard and choose 'Command Prompt (Admin)' or 'Windows PowerShell (Admin)' to open an elevated command prompt. 2. Type `diskpart` and press Enter. This will launch the Diskpart utility. 3. In the Diskpart prompt, type `list disk` and press Enter. This will display a list of all the disks connected to your system. 4. Identify the disk that contains the Windows active partition. Usually, it's the one with the most significant size or has the operating system installed. Note the disk number. 5. Type `select disk [disk_number]`, replacing `[disk_number]` with the number of the disk you identified in the previous step, and press Enter. This selects the disk for further operations. 6. Type `list partition` and press Enter. This will show you all partitions on the selected disk. 7. Identify the active partition, which is usually labeled as "System" or "Active." Note the partition number. 8. Type `select partition [partition_number]`, replacing `[partition_number]` with the number of the active partition, and press Enter. This selects the partition for deletion. 9. Now, type `delete partition override` and press Enter. This command will delete the active partition, but be cautious as it may lead to data loss or render the system unbootable if done incorrectly. 10. After deleting the partition, you may need to recreate it and reinstall the boot files using tools like Bootrec or a Windows installation media. Remember, these steps can be risky, so ensure you have a backup before proceeding, and only perform this operation if you understand the implications.

Step 1. Open a Command Prompt window and run it as an administrator.

Step 2. Type diskpart.

Step 3. Type list disk to view all disks.

Step 4. Type select disk n to display the disk numbers that contain the active system partition.

Step 5. Type list volume to view the status and details of the system partition.

Step 6. Enter select volume n.

Step 7. Type delete volume to delete the system volume.

Fix 3: Use Windows Installation Disc

If Windows can't delete the active system partition on this disk, you can use the Windows installation disc to complete this task. It's also easy to do with the following steps.

Step 1. Connect a Windows installation disc to the computer.

Step 2. Select the language, time, and keyboard method.

Step 3. Click "Install Now."

Step 4. Accept the terms of the license and click "Next."

Step 5. Select the custom or advanced installation type.

Step 6. Select the system partition and click "Delete."

After this, you can easily delete the system partition and install the new system.

Case 2: Delete Active System Partition in Dual System

For case two, there are two scenarios:

Situation 1: Two Different OS on Two Separate Hard Drives

Situation 2: Two Operating Systems on One Hard Drive

I've provided two solutions for the two scenarios. Let's examine the step-by-step process to resolve the issue where Windows cannot delete the active system on the disk.

Situation 1: Two Different OS on Two Separate Hard Drives

If you have two separate hard drives, you might also have two operating systems. One is on Partition C of Disk 0, and the other operating system is on Partition F of Disk 1. To delete the system partition, you'll need to utilize a third-party tool. You can download a tool called Partition Master for this purpose.

And proceed with the steps outlined in Fix 1: Utilize Partition Master Tool

Situation 2: Two OS on One Hard Drive

If there are two operating systems on the same hard drive, it might be due to a System Reserved Partition.

1. There exists a System Reserved Partition.

A System Reserved Partition may exist at the start of the disk. If you have two operating systems, the boot files for both will be saved in this System Reserved Partition. It is typically set as active by default. If you wish to delete a System Reserved Partition, you can follow the relevant link provided.

What is System Reserved Partition and How to Delete It

Essentially, if the System Reserved partition holds OS information or boot files, deleting it directly will result in an inability to boot the OS. In other words, the computer will not start if you delete the System Reserved partition without first verifying if it's safe to remove.

2. There Is No System Reserved Partition

If there's no System Reserved Partition, but you have two systems, you'll need to set the system partition you use as active. You can follow these steps to reboot your computer from the bootable CD, erase the partition, and then mark it as active:

Guide 1: Delete Partition using Partition Master Tool

Guide 2: Set Active

Step 1. Run the partition manager software. On the disk map, right-click the target partition and choose "Advanced".

Step 2. Next, select "Set Active" from the dropdown menu. Click "Yes". Then, choose "Execute 1 Task(s)" and click "Apply".

Conclusion

This article elucidates the reason behind the inability to delete the active system partition. Furthermore, the provided guide offers a comprehensive solution to the issue of Windows being unable to delete the active system partition on the disk. The utility, Partition Master, emerges as the optimal solution to this problem, efficaciously handling deletion of partitions, creation of bootable disks, and setting the system to an active state, be it a single or dual system configuration.

Frequently Asked Questions About "Windows Cannot Delete the Active System Partition on This Disk"

Here are some commonly asked questions about deleting partitions. If you're interested, please continue reading.

To delete an active partition in American English: 1. **Boot into BIOS/UEFI**: Restart your computer and enter BIOS or UEFI settings by pressing a specific key during startup. This is typically F2, F10, F12, or Del, but it can vary based on your system. 2. **Check Boot Order**: Navigate to the "Boot" or "Startup" menu and make sure your computer is set to boot from a USB or CD/DVD drive if you plan to use a bootable media for this process. 3. **Create a Bootable Media**: Download a trustworthy disk management tool like MiniTool Partition Wizard, GParted, or the Windows Media Creation Tool, and create a bootable USB or CD/DVD. 4. **Boot from Bootable Media**: Insert the bootable media and restart your computer. If necessary, change the boot order in BIOS/UEFI to boot from the USB or CD/DVD. 5. **Launch the Partition Manager**: When the tool loads, you'll see a graphical display of your disk partitions. Locate the active partition you want to delete. 6. **Delete the Partition**: Select the active partition and choose "Delete Partition" or "Format Partition." Be careful, as this will erase all data on that partition. 7. **Confirm the Deletion**: The tool will prompt you to confirm the action. Ensure you've selected the right partition and proceed with the deletion. 8. **Save Changes**: After deleting the partition, exit the tool and save the changes. Depending on the software, you might need to select "Apply" or "Commit" before quitting. 9. **Reboot**: Your computer will restart, and the active partition should now be gone. You can then create a new partition or allocate the unallocated space to an existing one. Keep in mind that deleting an active partition could impact your operating system, so back up important data beforehand. If the active partition holds your OS, consider using tools like System Rescue Disk or a Linux Live USB for a safer operation.

You can use tools like Partition Master to create a bootable disc and then delete the system partition. Alternatively, the Diskpart command is another efficient method.

2. What happens if you delete an active partition?

Usually, you can't delete the active partition because it's used to boot your computer. If you do, all your data and the operating system will be removed.

3. Can I delete the system partition?

You cannot delete system partitions using Disk Management in Windows. However, you can remove the system partition using third-party partitioning tools. Follow the steps outlined in this passage to proceed with deletion.