As it says on the box! (just the upgrade key),
Verified Purchase(What is this?)
This review is from: Windows 8 Standard Edition to Windows 8 Pro Pack, Upgrade Edition [Product key card only] (PC) (License)
Note: You do need to have a working OS to upgrade such as Windows Vista, with a current key, asthis producy gives an upgrade key.You will have to install Windows 8 from elsewhere such as a download upgrade or in my case another disc I used on another PC but could not use the same key on two machines.