Complete details for all the OS's I'm worried about:

- (XP) Open a folder. Tools, Folder Options. "View" tab. Advanced Settings. Scroll to bottom. Deactivate "Use Simple File Sharing".
- (XP) FIREWALL.CPL: enable the exception for File and Printer Sharing.
- (XP) FIREWALL.CPL: Edit the exception for File and Printer sharing and CHANGE SCOPE for each of the ports to be "any computer".
- (Vista+) Network and Sharing Center: Enable Network Discovery and File Sharing
- (Vista) FIREWALL.CPL: ADD PORT for port 139 TCP.
- (Win7) WF.MSC: add an INBOUND RULE to allow port 139 TCP.