Check this out:
How to Do Everything with Your Zune - Google Books
Instructions on how to connect your Zune as an external hard drive. This should allow you to copy the files from the Zune to your HD. Then what I would do is once you've successfully copied everything from your Zune to the hard drive, I'd do a hard reset of your Zune and resync it with the computer.
Oh and Windows 7 is a dream compared to Vista...