Before we jump in and start digging inside the case, lets review a few things. One of the most important things to remember is to be careful when dealing with components. Static electricity is not a computer's best friend. Make sure to ground yourself before touching components. This is especially a problem during the winter months.
SCSI drives are a completely different beast.
An IDE bus can have two devices connected to it, these two devices are known as the Master device and the Slave device. The Master device is always given priority over the Slave device when requesting CPU time to process information. In addition, most computers have two IDE busses, a Primary bus and a Secondary bus. The Master device on the Primary bus is usually always a hard drive as it is used to boot the system. Well, it depends.