Avoid Home Group like the plague!
On my machines, I'd set up a Home Group - which didn't work. So I removed it, and it immediately locked up all the hard drives on all the machines. I had to do a reinstall on the laptop, but fortunately Linux allowed me to unlock the desktop.
If you have a Home Group, just leave it there. Deleting it may cause disaster. Set up a Workgroup and make all machines members of that. Worked fine for me.