See also: Windows 10 release date and features For versions older than Windows 7, or non-genuine versions, you'll have to buy Windows 10 Home or Windows 10 Professional.
Windows 10 Home costs £99 from Microsoft and Professional will set you back £189. However, if you don't mind waiting for delivery, Amazon will sell you them for £77 and £112, respectively.
Firefox is one of the few browsers that continues to support Windows XP and Vista, and we expect to continue to provide security updates for users until September 2017.
Users do not need to take additional action to receive those updates.
You can read our hands-on review of Windows 10 here, but the bottom line is that it is certainly the best version of Windows yet.