Windows 7 Windows7 Premium to Professional

[andya]

I have a pc with Windows7 Premium installed on it. I also have a version of Windows7 Profesional on disc (complete version not upgrade). What is the best way to get the profesional release on my pc running : clean install or will the premium system propose an upgrade? If an upgrade should be possible, is all my data and existing programms of then deleted?

 

[reghakr]

Clean install,. no question about it.