sharing folder on Windows 7

Hi
i just want to share a folder with my other PC's connected to network, when i try to share it from "Share" option in right click menu, i get to user selection page, but how can i add, in drop down list i see only "home group" and "everybody".
in vista i used to connect through an guest account but here even activating guest account wont let other PC to log in, it says log in right(or something) is not set.

nope

figured it out
Password-Sharing had to be offed!

thanks