Sometimes, especially when upgrading your PC, you may need to perform a BIOS upgrade in order to update your system to accept a new hardware part or to fix a bug. For the average Joe, this procedure is quite obscure. In this tutorial we will give step-by-step procedures on how to upgrade your system BIOS.

What is BIOS anyway? BIOS is a program stored inside the ROM memory of your motherboard. There are three programs stored there: BIOS, setup and POST. As they are physically stored in the same memory chip, the majority of users call setup and POST “BIOS,” even though this is wrong, as they are three distinct programs. BIOS (Basic Input/Output System) teaches the system processor how to deal with basic things, like how to access the hard disk drive and how to write text on the screen. POST (Power On Self Test) is executed whenever you turn on your PC in order to test your system. It is in charge of that memory counting that happens every time you turn on your PC. And setup is that program that you run by pressing Del during POST (i.e., during memory counting) that is used to configure your motherboard.

So, “BIOS upgrade” really means an upgrade on the programs stored on the motherboard ROM memory. Even though the procedure name is “BIOS upgrade,” you actually upgrade all three programs (BIOS, POST and setup).

The way to update the motherboard ROM depends on the type of memory chip used in your PC. There are two types of ROM chips used in PCs: Mask-ROM (only on very old motherboards that cannot be updated by software) and Flash-ROM (on almost all motherboards, which is able to be updated by software). In this tutorial we will cover Flash-ROM.

If you have a very old motherboard (manufactured more than 10 years ago) that uses a Mask-ROM chip BIOS upgrade is only possible by replacing the chip with a new one containing the latest BIOS version. This chip can be bought on the motherboard manufacturer’s web site or at

On Figures 1 and 2 you see the most common physical aspect of the motherboard ROM chip, where BIOS is stored. The packaging found in Figure 1 is called DIP (Dual In-Line Package) and is used on older motherboards, while the packaging found in Figure 2 is called PLCC (Plastic Leaded Chip Carrier) and is used by current motherboards.

DIP BIOS ChipFigure 1: The BIOS chip. This kind of chip is called DIP (Dual In-Line Package).

PLCC BIOS ChipFigure 2: Another kind of BIOS chip, used by current motherboards. This kind of chip is called PLCC (Plastic Leaded Chip Carrier).

Gabriel Torres is a Brazilian best-selling ICT expert, with 24 books published. He started his online career in 1996, when he launched Clube do Hardware, which is one of the oldest and largest websites about technology in Brazil. He created Hardware Secrets in 1999 to expand his knowledge outside his home country.