- USB drive with 8GB of space or more.
- Windows 10 ISO image.
- Insert your USB drive.
- Download Rufus (<1MB, no-install) from here.
- Run Rufus and select your USB drive on Device field, if it’s not already selected.
- Click the DVD drive icon and select the Windows 10 ISO image.
- (optional) Rename the Volume label as you desire.
- Click Start and wait until it finishes.
- Restart your computer.
- During the boot press repeatedly the button that shows the Boot Device Menu. This button depends on your motherboard, but it’s usually one of these: ESC, F8, F9, F10, F11, F12. In this screen you should see all your storage devices, including your USB.
- Select the USB drive from the menu and Windows 10 installation will start.
Source: Rufus Official Website