Format C Drive Page

: Insert the USB, restart your PC, and enter your BIOS/UEFI settings (usually by pressing F2 , F12 , or Del during startup) to set the USB as the primary boot device.

Formatting your C drive (the partition containing your operating system) cannot be done while Windows is running. Because the OS is currently in use, Windows will block any attempt to format it through File Explorer or Disk Management to prevent the system from crashing. format c drive