: Use a tool like Rufus to flash the ISO file onto a USB drive. Select the partition scheme ( MBR or GPT ) that matches your computer's BIOS/UEFI settings.
: When prompted, enter your Windows 10 Pro product key. If you don't have one, you can select "I don't have a product key" to continue. You'll need to activate Windows later. windows 10 pro 21h1 gsm pack v27 install