Hello. I ordered windows 8 pro at 29,99 Euros at microsoft store. It says it is an update. I want to install it on a new computer. Do i have to install first windows 7 and then update to windows 8 (what will do a not clean instalation) or is there a way to install it directly in a computer with no windows on it ? to have a clean install of windows 8. Thank you for your answer.