( Note: If you are upgrading a Windows 7 or Windows 8.1 PC, you can actually use this tool to simply download and install Windows 10 directly to your computer. You’ll then choose your USB drive from a list of drives, and the tool will download the necessary files and put them on the USB drive. Installing from a USB drive is easiest, but you can find details on using a DVD and ISO file here. You’ll select the language and edition of Windows you want as well as whether it will be 32-bit or 62-bit, and then select the type of media you want to use.
You’ll need to run the tool, accept Microsoft’s terms, and then select “Create installation media for another PC” when you get to the “What do you want to do?” page. You’ll need a blank USB drive with at least 8GB of space (or a blank DVD) to put the Windows 10 installation files on.
You can download that tool using this link, or by going to this page and selecting “Download tool now” under the section titled “Create Windows 10 installation media.” Microsoft has a tool specifically for creating installation media.