Chris and TButler,
I'm sorry you're experiencing trouble. Windows Vista respects the settings
of 3rd party firewalls. We recommend you always run a Vista-compatible
Firewall. Please first check to ensure that the Firewall you're running is
Vista-compatible. If you upgraded an XP machine to Vista, and are running
the same firewall, it may be a firewall that isn't compliant with Vista.
If your firewall is Vista-compatible, then check the following:
a) manually enable Network Discovery and File & Printer Sharing exceptions
for file/printer sharing to work in Vista.
b) Check for any information message in Vista's Network and Sharing Center
which informs you about any installed 3rd party firewalls
c) Check Windows Security Center in Vista to ensure that only one firewall
is enabled. Start -> Security -> Security Center. Note that some OEM-built
machines come preloaded with a 3rd party firewall, and you may not even know
it.
d) Check your 3rd party firewalls settings to allow file & printer sharing.
Please post back with results.