For the following warning in oscommerce installation: Warning: session_start() [function.session-start]: open(/tmp\sess_5616cfa91211a8ef5ee94d09d21f7eb5, O_RDWR) failed: No such file or directory (2) in C:\wamp\www\catalog\includes\functions\sessions.php on line 67 As a solution they will suggest you to create a tmp folder in your root folder..