Just put a used motherboard into a system startup went pretty good (plug&play BIOS needs drivers)but it will not list the CD in My computer or Device Manager. I cmade it the sec. master .... no work. I made it the prim. slave .... no work. I made sure the BIOS would auto detect it and on the first screen the system detects the cd. What is it

Are you sure you don't have your cable reversed. The red or blue line goes on pin 1 on the mother board and closest to the power supply on the cdrom.

Use a bootdisk with cdrom support to test the cdrom. Windows can have problems with it if the motherboard drivers are not loaded.

Look in device manager in system in control panel for hardware marked with a yellow exclaimation or question mark. Sometimes when you change motherboards the OS will ask for the 98 cd to install hardware drivers but it won't have found the cdrom yet so it can't install them To get around this, boot with a bootdisk and choose cdrom support. Then at the a:\> prompt type: c: and return to change to the c: drive. Then: md win98 and return to create a directory on the HD. Then with the 98 cd in the cdrom type: copy d:\win98\*.* c:\win98 and return. This transfers the cab files to the win98 directory on the HD. Then reboot normally. When it asks for the 98 cd hit OK. It'll return an error message but give you the option of loading the files from somewhere else. Point it to c:\win98. You'll need to remove any remaining yellow marked items in device manager and do an 'add new hardware' to refind them or reboot and have the OS find them. Once the hardware is correctly identified the cdrom should show up.

If you changed the motherboard and restarted with a fully loaded hard drive, Windows has all the wrong drivers loaded for this motherboard. If you open Regedit and delete the key HKEY_LOCAL_MACHINE\Enum and then reboot, Windows will rediscover all the hardware and request appropriate drivers. This may cause many other drivers to require reloading, although Windows will usually pick them up on the drive.