How do I allow pass through access to a new shared drive on a Windows Server 2008 R2 box?

Question

I am trying to allow access to a shared drive on our server (running windows server 2008 R2) so that users (running windows 7) can access the files on it. However, whenever they try to connect, it prompts them for a password and says that "Access is Denied" even though it's set to share to everyone and the security settings are showing that everyone should have access to it. I read that in the network and sharing center I could turn off requiring a password, but when I go to look there all I find is Home, Public, Domain to allow discovery, and sharing, but no option to turn off credential requirements. How do I get these drives to share?