File & Printer Sharing not working on Windows Server 2008 R2
Try this: I opened the "Windows Firewall with Advanced Security" and clicked the "Restore defaults" button, and that solved the problem, and I can now share files again. You could also do this from the command line:
netsh advfirewall reset
....sounds like more than one person online found this to fix the issue. But...you could look and just make sure file and print sharing in the Windows advanced firewall has the right settings (check another 2008 server for details) before going to a full reset of the defaults. I'd backup the firewall config/settings first too.