session, error occuring when using session_start()

I have jsut recently installed a php development kit on my windows platform. Im interested in using the session functions but I am recieving this error when I use session_start(): Warning: open(/tmp\sess_540ded508edf231c47fe85bd970f936a, O_RDWR) failed: m (2) in d:\phpdev\www\phpdev4\samples\samp13.htm on line 4 Im assuming it has got to do something with the location it store the seesion id file. I had a look in my php.ini file and here is the the following configuration: [Session] ; Handler used to store/retrieve data. session.save_handler = files ; Argument passed to save_handler. In the case of files, this is the path ; where data files are stored. session.save_path = D:\phpdev\php\temp; ; Whether to use cookies. session.use_cookies = 1 ; Name of the session (used as cookie name). session.name = PHPSESSID ; Initialize session on request startup. session.auto_start = 0 ; Lifetime in seconds of cookie or, if 0, until browser is restarted. session.cookie_lifetime = 0 ; The path for which the cookie is valid. session.cookie_path = / Im not to sure why this is all ways happening. If anyone haas a solution or knows why this might occur could you please respond or email me at d_canil@hotmail.com. Much appreaciated Daniel