iTunes Movie Rental -- no go with Windows VISTA

I tried renting a few movies on iTunes for my kids today. My hope was to view them on a Windows VISTA computer which has a nice screen. However, I couldn't get it to work; 3 Apple support people later and still no success. The Apple support people were nice throughout the process, even though there doesn't appear to be a simple solution ... other than viewing the movies on my iPhone, which I plan to try next. It will take a few hours to download those moves, but that's OK. Anyway, it's been nice being on vacation. My hope is study a lot of Clinical Medicine before I start that rotation in the fall.