I'll like to discuss about a common problem faced when using two or more CD-ROMs or Hard disk drives in a system unit. When two hard disks, for example, are connected to the motherboard with one SATA, PATA or IDE cable, there's possibility for one of the two to read/write. It might not be that the other that can't read/write is faulty. You can also read a about Computer Storage Optimization . Checking up connected devices in BIOS settings might even display just one of the hard disks. If both CD-ROMs or Hard disk drives are ascertained of being in perfect condition then the problem might be the JUMPER SETTINGS. What are jumpers and how can you identify them on your CD-ROMs or Hard disk drives? Jumpers are conductors for bridging circuit. They are used to permit some settings. You can find jumpers at the back of your CD-ROM or Hard disk drive in some pins. The pins are usually four in number. Warning: Be careful when removing those kind of jumpers becaus