I downloaded windows 8 iso file from school (Microsoft DreamSpark) and I burned it into a DVD to install. However, I found I can also upgrade to windows 8 without clean installation. I ran upgrade assistance program, but it seems like I need to buy upgrade
windows 8 image or its DVD again.
I want to upgrade my operating system to keep my files or applications, not clean installation.
How to upgrade my operating system (windows 7) to Windows 8 with iso image file (DVD)? How?