Sharing a directory from Win7 Pro

[Fred Goldstein]

I kept a WinXP Pro system running for about 7 years, and had a couple of
directories (like the one I ripped my CDs too) set as public. This
allowed all of the PCs in the house to use them. Including XP machines.
(It's an obvious 192.168... WiFi network with every node in
"WORKGROUP".) Then I finally replaced it with a Win7 Pro system (home
grown with an A10). In most respects the newer machine works very well.
But its SMB (CIFS) file sharing doesn't work. Any ideas what I might
be missing?

Homegroup is of course useless since other machines include XP. And I
refuse to use IPv6, which seems to be a requirement for Homegroup. So
far what I've done includes taking the shared directory, giving it a
share name, giving "Everyone" read/write permission in File Sharing, and
checking "Allow" for full permission (Full Conrol, Change and Read) to
user Everyone in Advanced Sharing.

In the control panel's Advance Sharing Settings, I've got
Home or Work (Current Profile):
Turn on Network Discovery
Turn on File and Printer Sharing
Turn on [Public Folder SHaring]
Media Streaming is On
Enable File Sharing for devices with 40 or 56 bit encryption
Turn Off Password Protected Sharing
Allow Windows to manage Homegroup connections

Public:
(same settings for corresponding entries)

But I still get an error box that the share is not accessible; I might
not have permission.
The network path was not found.

And I can't print from the XP machine to the printer hosted on the Win7
machine. And I also can't print from XP to a printer hosted on a
different XP machine, which used to be possible.

Is it possible that the old machine played a network controller role
that the new one isn't doing?

Thanks in advance!