Plz help in retrieving my folder

Hello,
i have a very important folder in recycle bin of my vista desktop and i am using xp and vista both on my system. But now my vista shows that its deactivated and needs product key.
The product key i m entering is not valid now. So, i can reinstall vista. But problem is , how can i recover that particular folder without going to windows. I am able to go to xp which is in c drive and vista is in D drive.. Can some one help me , please ?