Not sure if it works with win 7 or not but I've used Magical Jelly Bean Finder in the past with no problems. Even on a non booting drive, which is a huge plus. http://www.magicaljellybean.com/keyfinder/
There is a screenshot that shows it working with win 7, but then states on another page it doesn't. But the site is also selling another keyfinder program for $25, so it may just be a marketing thing. Give it a shot anyway, and let me know if it does work.
Yknow, I posted my response in a rush, I kinda forgot to actually read that link. I suppose good information twice is better than bad information once though right?