This SSD will come with windows 10 pro already on it AND ACTIVATED! So if you built your own computer, need to replace your hard drive/ssd or just need a new copy of windows you will not need to worry about buying windows 10 and installing it, just install this SSD in the computer and you are ready to go! OR you can plug this drive into a USB port on any computer and it will boot that way as well. Will be brand new. Only opened to install windows 10 Pro and activate.