Need clarification on "Home Groups" and Microsoft "SharePoint Workspaces"

I  simply need to be able to work on a single WORD document on two laptops at home.  I thought home network groups might work, since I saw it working for Window XP computers before, where one computer's drive can be mounted on another as a network drive. But today, I seem not be able to get it work with my two Window 7 laptops. If anyone can send me a complete procedure how to set it up, I would highly appreciate.

I then noticed I can do  "SharePoint Workspace" for sharing folders, but I am hesitating to try because I was not sure how it works. Hope some of you expert can explain to be how it and if it will for my purpose.

What puzzles me is the relation between the "home network groups"  and "SharePoint Workspace".  Are they totally two separate features of Windows 7 or  I need use and work with them together?

Thanks

Ze