If you have a qualifying XP or Vista then you can use Windows 7 upgrade version, even if you don't have XP/Vista installed at the time.
If you have XP/VIsta on another HD then the install DVD will see it to allow Upgrade version key and configure a dual boot. If not, then do this:
Skip inserting the key upfront, use Custom install Drive Options to create and Format new partition(s), then after install immediately run an Upgrade install from the new desktop, which will force installer to accept Upgrade version key. Clean Install with a Upgrade Windows 7 Version
If your student download was only box files, then use the tutorial theog posted above to create an ISO. If you have the ISO, burn it to DVD or write to USB flashstick using theog's other link.
If you still need an ISO, MS makes good on failure to provide these at first for students here: http://gizmodo.com/5391268/microsoft...grade-problems