The system Basic Input/Output System, or BIOS for short, is one of the most important pieces of programming on any computer. Without it, the computer’s hardware would not be able to interact with one another upon startup. The BIOS controls many of the basic hardware configurations of your computer.
Please note any changes you make in the BIOS, as these changes can cause critical system errors. Jot down any changes which you make, as you make them. If the computer fails after a change has been made, simply restore any changes you made. If all else fails, almost every BIOS has an option to restore to the default settings. This will render your system operable, but is perhaps not the best in the event that a particular system is heavily modified from its original state.
To access your system BIOS, you will be prompted on system startup to press a key. You will be prompted for this just after your system counts its RAM. This will flash very quickly, usually in the lower right hand corner or middle left of the screen, it will last for about 2-3 seconds.
Once you press this key, you will be entered into the CMOS Setup utility. CMOS stands for Complimentary Metal Oxide Semiconductor. It is a form of RAM and retains your settings through a small watch battery. The CMOS Setup utility is essentially the list of available options which can be changed in the BIOS.
Depending on your system, there are many things you can view or change here. I will attempt to keep with only the most common features. In all CMOS Setups, you can view system information. This will tell you the brand, speed and model number of your processor, the amount of RAM and its speed, as well as BIOS version and some chipset specifics. This can be very useful in troubleshooting, to check the amount of RAM the BIOS is detecting against the amount of RAM you have installed, or to check the detected speed of the processor against the actual speed it should be. It is a common problem for early versions of a BIOS not to detect the full power of your processor and memory, simply because the newest versions of these hardware devices were not applicable at the release time of your BIOS chip. This is something to be aware of when upgrading processor or memory on an older motherboard.
Probably one of the most common problems with a BIOS, which can be edited from any CMOS Setup utility, is having the time and date settings lost. This can be particularly annoying, because most BIOS’s will prompt you with this error every time the system starts, until the problem is resolved. These can be manually entered through the CMOS Setup utility.
The CMOS Setup utility will allow you to view all of your IDE drives. This includes hard drives and optical drives. Although Floppy drives are not IDE, they will most likely be found in the same place, or close therein of the IDE drives. There is little you can do here, aside of verifying that the system is detecting all of your installed hardware components and detecting them properly. On some older BIOS versions, it may be necessary to access this in order to manually type in the number of Tracks, Heads and Sectors.
Another very common feature of the CMOS Setup utility is the ability to choose boot order. This is very important, as many people do not realize that they can change the order in which the system looks for bootable devices. Your systems boot order, by default, will check the floppy disk drive first, if you have one. This is what causes so many headaches for people who forget they left that floppy disk in their system and now cannot start the machine. In the CMOS Setup utility, this will be referred to as either Floppy or as “Removable Media”. After the floppy drive, it will be set to search the optical media drives, thus CD Rom or DVD Rom drives. Last, it will check your hard disk drive. It is set to search these other devices first to aid the trouble shooting procedure. If you were to set this order to search your hard drive first, your system would boot considerably faster, however this is not recommended, as it is easily forgotten that this was changed in a time when you must fix the computer.
Most people have heard the term “over clocking” at least once in their computing experiences. This term refers to sending more electrical pulses to the processor per second. This does in fact increase your computers speed, however it can be extremely harmful to your computer. The clock speed of a processor can be set in some CMOS setups. This, in fact, is very vendor specific, and will vary for different CMOS’s and different processors. Some processors or CMOS’s will not allow the clock speed to be changed. However, it can usually be viewed from the CMOS Setup utility, if not changed.
When exiting the CMOS Setup utility, you will have a number of options. Generically, these options are “Save Changes and Exit”, “Discard Changes and Exit” or “Restore Defaults and Exit”. The third is a good bet if you have system failures after changing some of the BIOS settings.