'Autorun' and disc recognition disabled

Hi,
somehow 'autorun' and recognition of external discs seems to have been disabled on my system. When I put a music cd in my d: or e: drive, it does not autoplay, when I put a blank cdrom or dvdrom in nero doesn't open. Also, when I connect an external hd (several times previously connected ok before), it does not load its drivers to allow it to be read. It will show up as a drive but as being empty/not formatted.

What can I do to retrieve this functionality? I am running XP SP3.

 

autoplay repair wizard