[tharbert]

System Builder is for preinstallation on a new personal computer for resale. Technically, you can't legally "upgrade" using a system builder license but it would probably work just fine. There seem to be plenty of Windows upgrade packages priced the same as the system builder versions. Get one of those.

And, yes, Win 7 and 8 both come with a the ability to delete/create partitions and format the resulting drives as part of the installation process. My experience is that multiple (non-system) partitions are a waste of time. So, when you go to advanced disk options, delete all the partitions (note 1) then create one large. The system will ask to create it's own little partition. Let it.

Note 1: Most computers come with a hidden recovery partition that contains the OEM windows installation files. You press a function key at start-up to access, that function key being different from vendor to vendor. If you are moving to an upgraded version of windows, that hidden recovery partition becomes useless.