A:Answer You can download the "Windows Media Creation Tool" from Microsoft (just search for it). Run this tool on your computer, and it will create a bootable USB to install Windows 10 from.
You will also have to enable booting from USB devices in the laptop's UEFI/BIOS before you can boot from it.
Windows will automatically install all drivers for you, but you will need to manually reinstall all the extra Alienware, Dell, & NVIDIA software (if you want it) from their respective websites. The entire process is quite straightforward and relatively painless.