title: Sql OpenDataSource doesnt work with unc path to excel or csv files
body: <p>I have the following across several procs in our database to automate reading in excel files:</p>
  
  <pre><code>SELECT *   
   FROM OPENDATASOURCE('Microsoft.ACE.OLEDB.12.0', 
   'data source=\\server\Uploads\Unprocessed\uploadedfile-Mailing.xls; 
   Extended Properties=Excel 12.0 XML;HDR=NO;IMEX=1;')...['_Export_Finished$'] 
  </code></pre>
  
  <p>We recently added a few servers and now we appear to be having permissions errors using opendatasource specifically... if that command is run as SA it works fine, if its run as sql agent or any other user it bombs out with the following extremely descriptive error:</p>
  
  <blockquote>
    <p>OLE DB provider "Microsoft.ACE.OLEDB.12.0" for linked server "(null)" returned message >"Could not find installable ISAM.".
    Msg 7303, Level 16, State 1, Line 1
    Cannot initialize the data source object of OLE DB provider "Microsoft.ACE.OLEDB.12.0" for >linked server "(null)".</p>
  </blockquote>
  
  <p>However, when we use openrowset like such:</p>
  
  <pre><code>select * from 
  openrowset('Microsoft.ACE.OLEDB.12.0',
  'Excel 12.0     Xml;HDR=no;IMEX=1;Format=xlsx;Database=\\server\Uploads\Unprocessed\uploadedfile-Mailing.xls',
  'select * from [_Export_Finished$]')
  </code></pre>
  
  <p>, the query fires fine independent of what user is firing it... it'd be better for opendatasource to work instead of having to swap out everything to openrowset... any idea why one is working over the other?  these are 64 bit servers but that shouldnt matter considering openrowset works.  Any help would be extremely appreciated!</p>