title: One machine on network cannot connect to SQL 2005
body: <p>I've got a small Windows network with 3 machines. One of them has SQL 2005 installed. As of last week, the other two machines have had no problems connecting to the SQL instance.</p>
  
  <p>Today, one machine - running Vista, if that matters - all of a sudden cannot connect. I get the generic message saying "A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections."</p>
  
  <p>I'm pretty sure everything is set up correctly on the SQL 2005 box, because the third computer on the network still connects with no problem.</p>
  
  <p>Vista computer has no firewalls set up, nothing has changed with the exception that I created a connection to a VPN a few days ago. When connected to the VPN, local network connectivity is hosed, but I've double checked many times that I am NOT connected to the VPN when trying to access SQL Server. I mention this only because it's the only thing I can think of that's changed.</p>
  
  <p>I've rebooted all computers many times. No change.</p>
  
  <p>I'm connecting via SQL Integrated Security. The login works fine from the third machine. </p>
  
  <p>One other weird thing on the Vista box. Occasionally - maybe 5% of the time - it'll connect, but then when trying to access a table (like, just right clicking and choosing "open") it pauses then gives an "unspecified error."</p>
  
  <p>Any ideas? I'm totally perplexed. This has been working for about 18 months without any errors, and I can't think of anything that's changed other than the VPN connection mentioned above. And just to reiterate - I am definitely NOT connected to the VPN when I'm getting this error.</p>