Although I'm not sure, I think you are trying to load the file from the wrong place.
Normally, after a successful upload, your file will be given a temporary filename. You can read this filename as
$HTTP_POST_FILES['userfile']['tmp_name']
where 'userfile' is the name of the field in your form. Also, dont forget this bit inside your form tag
enctype="multipart/form-data"
Like i said, you should probably not be trying to read a find in c:\logo.gif anyway (unless you are running php on windows).
For a full explination read the manual page here...
http://www.php.net/manual/en/features.file-upload.php
