(Hi; I've been a lurker here for a while, and have had some great info - thanks all!) I bought a copy of Windows 7 pro from software4students 3-4 years ago, for my son's PC. I received a media DVD disk titled: October 2009 Systems Student Media Microsoft Windows 7 professional 32-bit x86 Upgrade Part No. FQC-03121 X16-17573 And it installed and has been running fine on his PC. However, he's now built a new PC and we want to install Windows 7 on that (and remove it from the old one). But he'd like the 64-bit version and I don't have media (the above is 32-bit). I've tried using the key with the generic install media from digitalriver, X15-65805, but that doesn't accept the licence key (I guess because it's an upgrade licence). Under the assumption that my key will work for both 32- and 64-bit versions, could anybody please help and advise where I might get an ISO of the equivalent 64-bit media to the above? Thanks!