First do a virus scan. Then scan your registry for noide. Might also try to boot from a boot disk from what ever operating system you are using and try a fdisk /mbr twice. Or go into safe mode and remove the ide controller. Might also try a different cdrom or place that one as slave on the primary or in another system. Also uncheck DMA if it is set in the cdrom properties. If it is showing on post, but not in windows then chances are the mobo is fine. It is either the cdrom or windows.