latest update
Right, I tried a couple of your suggestions and the one that seems to be working at the mo is via windows update. Using this I managed to isolate the recent updates that were related to win7, logically assumimg I could ignore the Office 2007 and IE8 updates. I narrowed it down to 3 updates and individually uninstalled and reinstalled them until I found the offending file. But the main prob has been the keeness of the laptop to try and reinstall the offending file!!!!
I have now "hidden" the offending file and setup Windows Update to notify me about any attempts to install updates automatically. This all seems to have allowed my DVD drive to remain in existence, but I still am not totally happy, Microsoft chucks out updates every few days and I now am going have to very closely monitor all of these attempts instead of allowing it to update automatically. I do feel slightly cheated as upto now Win 7 has performed and updated faultlessly.
Ultimately, I need to find why this particular update causes my dvd to dissappear, otherwise I will always be wary of future updates repeating this problem and the more security updates I isolate and prevent from loading the more vulnerable my system will become.
Many thanks all who gave their time to respond
Frazhm