Windows 8.1 Professional ISO download

Hi,

I have a freshly built machine next to me.
I have a medialess windows 8.1 pro key.
I have a usb drive.

However I do not have a windows 8.1 pro ISO to put on said USB drive.

Does anyone know where I can get one from?

Not sure if this will work or not?

http://blogs.technet.com/b/canitpro...-how-to-download-the-windows-8-1-pro-iso.aspx

Brilliant, thanks