What a long thread.. And the solution, reinstall the OS? Heh!
It's probably too late, but how about some systematic approach to things with thought in it instead of blindly following random steps?
First, what you want the problematic machine to do? To share files or access resources shared by others?
Let's assume the latter, OK?
Starting from bottom up:
Work with IP addresses only for now. Name resolution is an extra layer of confusion. Disable all your software firewalls. Even better if you just plain uninstall all firewalls, VPN software, packet sniffers. You can put stuff back when it works.
- Does the server work? (Yes it does)
- Can you ping the server? (Yes you can)
- Can you reach the file services on the server?
Try "telnet server.machine.ip.address 139". If you get a blank black window with a flashing cursor, then the network connection works.
- The moment of truth.. Can you see the shares on the server?
Put in \\server.ip.address in a Windows Explorer window.
- Check whether you have Client for Microsoft Networks installed. (See the properties of your Local Area Connection and make sure you see the relevant entry and it has a check box in front of it). Uninstall and reinstall the component.
- Check whether the Workstation service is running. (This and its dependencies is the only thing you need to access file shares).
- See the Event Viewer for any errors pertaining to Workstation service or any of the dependencies.
Try that stuff and back with results.