BIOS stands for Basic Input / Output System and it simply provides a set of instructions to your computer, telling it how to start, and how to interface to the first 'Boot' device.
When it reaches the first boot device, it then receives further instructions from there to follow up, and eventually loads your operating system if everything is OK.
However, at start-up, your computer you can tell whether the drive has been detected by the BIOS or not.
Before getting too worried, power down the computer and unplug the hard disk and check if all the jumpers on the hard drive are set correctly according to the hard disk manufacturer's instructions. Incorrect jumper setting can prevent the hard drive from being detected by the BIOS. In some hard drives such as IBM and Hitachi, incorrect settings will corrupt the data and damage the logical structure of the hard disk.
Again, at this stage, you need to consult a Rockingham I.T. Solutions Technician who would advise you what to do next.
