My DVD worked perfect for the past 2 years , now it keeps disappearing after a while from Windows 7 and Device Manager . If I reboot the system it will reappear and work as it should , but after a while ( one hour or so ) it will disappear again . I tried to reinstall the drivers, no result ; I tried to do the registry thing ( deleting upperfilters and lowerfilters ) but the registries aren't there . What can I do to make my DVD visible all the time ?