My opinion on windows 10 is a bit mixed up.Seems the installer they have causes a lot of trouble when installing and it can crash as it has happened to me and many others,lots of games cant be played yet there(dont know how many or if its even true but random gamers told me they cant open games),it may cause lagg after you upgrade the pc so better format it too.For the good side they have the nice looks of windows 8 with the menu of windows 7 which i love,needs less space and from what i have seen in my other pc some games run better.