Yeah you're going to need a license key to go along with that install. Simply having the software isn't going to cut it. Make sure to factor a Windows 10 home (or Pro if you need the bells and whistles) 64bit edition in to your budget. OEM is the cheapest way in to it, but it ties your license to your motherboard. So if you upgrade later on it can cause a problem reactivating with a new build. A retail copy is more expensive but you can migrate the license if you do a new build later on.