Fixed – Windows cannot format the system partition on this disk

Updated on October 23rd, 2020

This post is going to fix “Windows cannot format the system partition on this disk” issue. If you are bothered by same issue, you can follow solutions in this page to format system partition on Windows 10/8/7/XP.

Symptopm of “Windows cannot format the system partition on this disk” issue

This error may appear on various occassions, preventing you from formatting system partition hard drive. When you try to restore computer and failed with unknown error. The procedure hang for more than an hour and you might end up with pressing power button. Then you tried once again but failed with same issue. If you try to run it again, you may get error message like drive is full and does not have enough space. If you try to continue with a different partition, and the problem still exists. If you try to format C drive, you get error message “Windows cannot format the system partition on this disk”. Same error massage may appear on a totally different scenario, and here are two real-world cases of this error:

“Hello, I come here to seek help from computer experts. I was trying to format one of my hard drives, but Windows did not allow me to do that. I tried to format a non-system drive, but Windows kept saying it is a system partition, and it cannot complete the formatting. I tried remove the disk and reconnect it to my PC, but Windows got booting issue. That’s weird. It really confused my why Windows always takes it as system drive. My computer is running Windows 7. Do you have any idea on this problem? Thanks.”

“Hey guys, please help me out! I’ve installed Windows on my old laptop. The hard drive is divided into two partitions C and D. I want to format D drive but get message saying “Windows cannot format the system partition ont his drive”. Why d drive is the system partition. I do not understand what is going on. Do I need to reinstalling Windows? Can this issue be fixed by modify drive letter for these two partitions?”

Why Windows cannot format the system partition on this disk

System partition is the one used to install Windows, and it holds operating system files, boot information such as boot.ini, NTLDR, bootmgr, etc. On MBR disk, system partition is primary partition and marked as activate. System partition is usualy assigned with drive letter C. There is only one partition can be marked as active, and it cannot be formatted while system is running. If you try to format system partition, you have to do it on Pre-OS environment. Once system partition gets formatted, computer won’t be able to find system to boot and you’ll get a black screen. Thus operating system does not allow users to format system partition in File Explorer or Disk Management.

If you right-click C drive in Windows Explorer and select “Format” option from context menu, you will get an message on a popped-up box saying “You cannot format this volume. It contains the version of Windows that you are using. Formatting this colume could cause your computer to stop working. Formatting disks and drivers FAQ.” That means you cannot format C drive while Windows is running. How to format system C drive on Windows 10/8/7? You can follow these steps to format C drive.

Method 1: Format system/C drive using Windows install disc

If you have a Windows Setup disc or flash drive, you can follow this method to format C drive easily. If you do not have access to Windows installaciton disc, you can move to Method 2 which formats system drive with free partition manager software.

  1. Insert Windows instllation disc and restart your computer.
  2. Press the key prompted on screen and follow instructions.
  3. Select language and other reference, and click Next.
  4. Click “I accept the license terms” and click Next on the “Please read the license term” page.
  5. Click Custom if you are aked to choose the type of installation, and click Drive options (advanced) on the page “Where do you want to install Windows?”
  6. Click System partition and click Format. Then select formatting option that you want.
  7. Click Next when formatting completes.

Method 2: Format Windows system partition on hard disk with free partition manager

Eassos DiskGenius is able to format hard drive or partition on Windows 10/8/7/XP. It offers functions to create bootable media with which you can boot computer and run the program on WinPE environment. Here are steps to format system partition or hard drive:

Step 1: Insert a USB flash drive to your computer and laucn Eassos PartitionGuru.

Step 2: Select the USB drive on the main interface, and click Tools – > Create WinPE bootable USB drive of DiskGenius.

Windows cannot format the system partition on this disk

Step 3: Click OK button on the popped-up window. Wait for a while and the bootable madia is created.

Windows cannot format the system partition on this disk

Step 4: Restart computer and enter BIOS to change boot order so that your computer is configured to boot from bootable media instead of hard drive.

Windows cannot format the system partition on this disk

Step 5: Save changed and restart computer again. Then your computer will boot from the media and launch Eassos DiskGenius WinPE version.

Step 6: Select the system partition in the software and click Format button.

Windows cannot format the system partition on this disk

Step 7: Set formatting options for C drive and click Format button.

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