The media creation tool can be used to upgrade your current PC to Windows 10 or to create a USB or DVD and install Windows 10 on a different PC.
Here’s a quick look at the steps to get Windows 10 installed on your PC using this tool.
Download the tool
Find the media creation tool on the Software download page.
There are two versions of the tool, one for a “32-bit operating system” and one for a “64-bit operating system.”
When you’re asked, select Run (or choose to Save the tool if you don’t want to run it now)
and choice if update the PC or if create a media support.
In the first case, will be downloaded all the installation files from internet and will start the automatic procedure of Windows 10 install (work only with Windows 7 SP1 e Windows 8.1).
[original source page] http://go.microsoft.com/fwlink/p/?LinkId=616447