Create Bootable USB without any software on Windows 10:

• Insert your USB flash drive to your computer.
• Search for ‘cmd’ in Windows 10 from the taskbar, Command Prompt will appear. Alternatively, you can also open the  Command Prompt by pressingwindows+R at the same time and typing in ‘cmd’ in the ‘Run’ window and hitting enter.
• Right click on Command Prompt and select ‘Run as Administrator’ in case you have searched for cmd in the Windows 10 Taskbar.
• Once the Command Prompt window appears, type diskpart and hit enter. Wait until the diskpart utility runs in another window.
• In the new diskpart window, type list disk and hit enter. It will show you all active disks on your computer.

Most probably, you will see two Disk types.

• Disk 0 for hard drive and,
• Disk 1 for your USB Flash Drive with its total capacity.

Since we are going to work on to create bootable USB drive, we will work with Disk 1.

• Type select disk 1 in the same windows and hit Enter. You will get a message ‘Disk 1 is now the selected disk’. That means, any further operation that you do will affect your disk 1 directly.
• Type clean and hit Enter to remove all of the data in the USB drive. Clean command will format your bootable drive. You will get a message like ‘Diskpart succeeded in cleaning the disk’.
• Type create partition primary and hit Enter. You will get a message likeDiskpart succeeded in creating the specified partition.
• Type select partition 1 and hit Enter. It will choose partition 1 for setting up it as an active partition.
• Type active and hit Enter. It will activate the current partition.
• Type format fs=ntfs quick and hit Enter. This command will format your current partition as NTFS file system quickly.
• Type exit and hit Enter. Exit command will close the Diskpart program. But do not close the command prompt Windows.

Now before we proceed, let us assume that the USB drive is the G: drive and the DVD installer is located on drive E:. And, you also have inserted a DVD inside the DVD drive from where you want to copy the data to create a bootable USB drive.

By default, Command Prompt’s active directory for Administrator permission is on C:\Windows\System32>. We will navigate Command Prompt to set on DVD (E:) as its active directory. Remember there should be a DVD inside DVD installer.

• Just type E: then hit Enter, and then the active directory is changed to E.
• Type cd boot and hit Enter. Now the active directory is changed to E:\boot>
• Type bootsect /nt60 g: and hit Enter. It will create the boot sector on G: drive (USB Flash drive).
• Type exit and hit Enter to close the Command Prompt.

Until this step, we have been successfully able to create a bootable USB drive and the flash drive is ready to be used as a boot media.

To install Windows from a bootable USB drive, we just need to copy the whole installation files contained on the DVD installer to the USB flash drive.

• To do this, open the Command Prompt as in previous steps.
• Once the command prompt is open, type xcopy e: \ *. * G: \ / E / H / F and then press Enter. Wait until all the files in the DVD installer are copied onto the flash drive.

Now bootable USB drive is ready to be used for installing Windows from the Flash drive and you’re done.