Mine had it pre installed, but needed authentication via the code on the box. Windows a lot had of updates to download and install when I connected to the internet for first download and install, so don't expect it to be useable out of the box.
By David Haxton on 16 November 2014
The operating system (Windows) and applications such as Office take up several GB. There's also a recovery partition: use Google to find out how to back-up your recovery partition to an external drive so you can use that space. Here's a tutorial on Youtube http://www.youtube.com/watch?v=uX_wqf9vY3Y
By Alec Smart on 06 September 2014