[McGruff]

You beat me to the file sharing page. It maybe as simple as this

"The default workgroup name in Windows Vista has been changed to WORKGROUP. In Windows® XP Home Edition, the default workgroup name is MSHOME."

I'm running Vista and the other 2 running XP and seem to remember having this problem.

[JSteff]

Yeah, I was helping a friend and it was that simple if I recall. There was also a reg fix to a related issue with the sharing locations. I am trying to look that up too.