[ddeerrff]

I have a networking issue that is causing me to pull out my remaining hair. Afraid I might have things totally messed up.

Cable modem (Motorola SB4100) connected to wireless router (Buffalo).
WinXP desktop hardwired to router
WinXP laptop connected wireless
Win Vista laptop connected wireless
Win7 laptop connected wireless

All machines have no problems connecting to the internet. The problem is in file and printer sharing.

The XP desktop (with printer) can see only itself.
The XP laptop can only see the XP desktop (doesn't seem to even see itself)
The Win Vista laptop is my son's and almost constantly in use online gaming, so I have limited info on it.

The Win7 laptop always sees itself and the Vista laptop, but only sees the XP machines intermittantly. They will be there for a while, and then gone - then later they may be back. I need the Win7 machine to be able to consistantly access the printer on the WinXP desktop.

All machines have at least one folder set to share. Each machine has a unique name. All machines are on the same workgroup. All machines pull an IP and DNS via DHCP, and are shown on the same subnet (255.255.255.0). All machines have "File and Printer sharing for Microsoft networks" installed and enabled. The Win7 machine has both IPv4 and IPv6 enabled. The Vista machine may have IPv6 disabled. Both WinXP machines have only the Windows firewall installed and these are set to allow file and print sharing. Disabling the XP firewalls made no difference.

On both WinXP machines.... If I open 'My Network Places', 'Entire Network', then 'Microsoft Windows Network', I see an icon for the name I gave to the workgroup (aaronco). Clicking this icon gives me an error that says (paraphrasing) it is not accessible, that I may not have permission to access the network or that the network may have as many connections as it can take. I get the same error on both the Desktop XP machine and the XP laptop.

Help would be appreciated.