title: invalid UNC path with openrowset
body: <p>I've created a folder called Public off the root of my C:\drive and have shared it with "Everyone".  I've also given NETWORK SERVICE read rights. But when I issue the following query in SQL Server 2008-R2, the error is that "\\FOO\public\my.csv" is not a valid path:</p>
  
  <pre><code>SELECT * 
  FROM OPENROWSET (
    'Microsoft.ACE.OLEDB.12.0', 
      'Text;Database=\\FOO\public\my.csv; ', 
      'SELECT * from my.csv'
      )
  </code></pre>
  
  <p>The 64-bit driver of ACE is installed. I'm on Windows 7 x64.  It's a 64-bit version of SQL Server.  My PC's machine name is "FOO".  It doesn't work with a simple <code>c:\public</code> path either.</p>
  
  <blockquote>
    <p>OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)"
    returned message "'\FOO\public\my.csv' is not a valid path. Make sure
    that the path name is spelled correctly and that you are connected to
    the server on which the file resides.".</p>
  </blockquote>
  
  <p>I've configured the server so:</p>
  
  <pre><code>exec sp_configure 'show advanced options', 1
  RECONFIGURE;
  exec sp_configure 'Ad Hoc Distributed Queries', 1
  RECONFIGURE;
  </code></pre>
  
  <p>What else to check?  Thanks</p>