PHP - Temp Files On Windows Iis Server

I set up functionality for a client that got moved to their server after I wrote and tested the functionality.  It does not work on their server and I am trying to trouble shoot the problem as I do not have ftp access to the server. I believe that I have narrowed it down to either I do not know how to access the temp files on their server, Windows IIS, OR the security on the server is not allowing me to upload to the temp files. Here is the form used to upload to the server.   <form  enctype="multipart/form-data"  action="#" method="post" >
    <input type="hidden" name="upload_csv" value="TRUE" />
    <p><label  for="userfile">Upload CSV:</label>
    <input type="hidden" name="MAX_FILE_SIZE" value="45000000" />
    <input type="file" id="userfile" name="userfile" title="userfile" value="" /></p>
    <p><input  type="submit" name="upload_csv" value="Upload CSV" /></p>    
</form>     Here is the test code:   <?php
$csvfile = $_FILES['userfile']['tmp_name'];
$size = $_FILES['userfile']['size'];

if($_POST['upload_csv']){
    //---------------------------------validation code here
    if($problem){
        echo '<div class="error">Did not pass validation</div>';
        include("upload_csv.inc.php");
    }else{
        if (($handle = fopen($csvfile, "r")) !== FALSE) {                 //--------------------------------------------------------------this is where the code that imports the data from the csv and to the database goes
                echo '<div class="message"><p>CSV has been opened!</p></div>';
        }elseif(!$csvfile){
                echo '<div class="error">Problem #1</div>';
        }else{
                echo '<div class="error">Problem #2</div>';
        }
    }
}else{
    include("upload_csv.inc.php");
}
?>     This code generated the error message: Problem #2. One more bit of information: the permissions on the server is set so that nothing can be uploaded by an external script. I do not know much about servers, but it seems to me that because the security is so tight on the server, the security is the reason that this does not work...???   I appreciate help with this. I just am not knowledgeable on how the $_FILES['userfile']['tmp_name'] code actually works?