The university has a campus-wide agreement for Windows upgrades, as well as for Microsoft Office for Windows and Mac OS X.
CD or DVD images may be downloaded from the OIT Technology Products web site.
The agreement covers all computers which are owned or leased by the University of Minnesota.
To install some of these products you will also need a software product key, which is available alongside the downloads. Current versions of Windows and Office register themselves with a license server, so don't require a key, but they do need to be (at least periodically) on campus to communicate with the server.