uploading

[eluser]anaxamaxan[/eluser]
If you're following the code in the user guide, your controller class should be Upload, and the method is do_upload. So, your form action value, i.e. the form open in your view should be
form_open_multipart('upload/do_upload');
http://localhost/CodeIgniter/upload/do_upload

Are you putting the Upload controller in a subdirectory, i.e. application/controllers/search/upload.php ? If so, be sure your form_open_multipart() matches that path.