I have two systems with the same problem. On the first system my cdrom is the primary master w/hdd as the slave. My cdrw/dvd combo is the secondary master which, works fine. The second system sports a dvd/cdrom as the primary master w/hdd as a slave. My cdrw on the 2nd system is the secondary master which also works fine. All information from this point on refers two both systems. The devices on the secondary do not work properly. My OS is Windows XP Professional. The bios and windows recognizes all hardware and ID's as they should. Device Manager shows that these devices are working fine. All physical aspects of these drives work as they should. When a disc is inserted in the drives I am unable to access the media contained therin. Regardless of the software used to access the drives. When I try to access the media through Windows Explorer, I get an error message. ( G:\is not accessible. Incorrect funtion. ) I have tried several different configurations, swapped drives with other computers and everything works fine. Except that the first cdrom drive is inaccessible.