I have Windows 8.1 and 7 systems in a Homegroup, and I find that after rebooting the 7, I have to login before its shared folders appear in 8.1's view of the Homegroup. Until I do, I see "This PC is currently unavailable" in File Explorer. This is despite the fact the shares are available through Network (user names and passwords are the same). ISTR that when both systems were running 7, I did not need to login. Any ideas?