Ive formatted my toshiba satelitte, now i want to re-install windows 7 home prem, i have a product key but no disk, how do i d

[wobbiexr8]

My toshiba satelitte laptop had windows 7 home prem installed on it but after a few years of clutter i decided to format it,so now its completely wiped. How do i reinstall windows 7 without an installation disk, the product key is on the back of the laptop?

 

[Emerald]

http://www.tomshardware.com/answers/id-1988138/official-iso-downloads-users-key.html