New
#11
Take a look at this:
Windows Anytime Upgrade - Upgrade your Windows 7 edition - Microsoft Windows
No install files needed.
Only the Upgrade key is need.
Anytime upgrade only adds-on the Programs & Features from version to version.
Windows Anytime Upgrade - How to
You can also use Pro, if you buy from a Retailer, you only need to be online to actvate.