Given the steady trickle of BIOS-related questions that I get via email, I think that it's time for a post to demystify BIOS updates and the role they have in keeping your PC in tip-top condition.
Note: Even though the BIOS is now legacy and has been superseded by EFI, there's no sign of the BIOS disappearing any time soon.
BIOS stands for Basic Input/Output System and refers to the firmware that is run by a PC when it is first powered up. The primary role of the BIOS is to get the hardware up and running so that the OS can take over (I've simplified things here dramatically, but if you're the kind of person who can spot that, chances are you already know what I've skipped over!).
Put in simple terms, without the BIOS the PC (or specifically the motherboard) is a dead stick.
Updating the BIOS
When you update the BIOS (also known as flashing the BIOS) what you are doing is taking this fundamental code and updating it with new code. Unlike updating an OS or software where it is possible to update a particular part of the code, almost all BIOS updates are complete updates (I say almost all because if I say all someone is bound to post something that'll prove me wrong!).
BIOS updates are carried out in one of three ways:
- Using a DOS-based updater
- Using a Windows-based updater
- Through a specific update program built into the motherboard and accessible through the BIOS
Note: I've left out the BIOS update that involves physically replacing the BIOS ROM, a procedure that's died away over the years.
OK, time for lesson #1. If you want to dramatically reduce the chances of hosing your system, never, ever, update the BIOS from within Windows. I know that most motherboard manufacturers make a Windows updater available, and I know that it's a hassle to have to make a boot disk (or boot disc, if you don't have a floppy drive), but if you're going to go to the bother of flashing the BIOS, do it right, and in my book doing it right means not flashing through Windows. Why? Simple. Of all the trashed BIOSes that I've come across (more of this in a moment), a good 90% were trashed because the Windows-based updater didn't do what it was supposed to do.
Should I flash my BIOS?
Now we get to the nitty-gritty.
My advice on this matter is clear - Don't flash your BIOS unless you have a clear idea of why you are doing so. Good reasons might be that you're fixing a known problem or maybe adding support for a new component (such as a CPU). Motherboard manufacturers do a good job of documenting what BIOS updates do, so make sure that you read up first. Bad reasons for updating a BIOS include randomly trying to fix a problem or hoping that the update will give you access to a fantastic new feature or turbo boost your system's performance.
As a rule, there are only two occasions when I'll flash a BIOS on one of my systems:
- When the Motherboard or PC is new (that way, if it's trashed, the system goes back)
- When there's a darn good reason for doing the update (as a rule I find that if I buy a cutting-edge board then there can be a lot of BIOS updates released over a short period of time, and many of these can be critical updates - the pain of being at the cutting edge!)
Anything that falls beyond these two reasons is either considered experimental or play.
The update process
Before you update a BIOS you need to know that it can go one of two ways:
- It goes well, and the system boots up find at the end
- It goes horribly wrong
The trick is to minimize the chances of things going wrong. How do you do that? Here's my set of top tips:
- Think carefully as to whether you need to upgrade the BIOS.
- Never try to rush an update.
- As I've already said, don't flash the BIOS through Windows, ever!
- Only download BIOS updates from reputable sources - your motherboard manufacturer if you built the PC or OEM if you bought the PC ready-made. BIOS updates and dodgy download sites don't mix!
- The BIOS updater tool (if using a DOS-based utility) and the actual BIOS update must be the right one for your system, down to the revision or model number). Close enough isn't good enough - if it's not the right update you will kill your system! Check, double-check, and then check again that you have the right update.
- Make sure you keep a note of your current BIOS settings - even if you haven't made any changes, the OEM might! (Taking photos of the BIOS screens with a digital camera is a good way of quickly capturing all the info).
- If at all possible, put the PC being updated onto a battery-backup UPS - you don't want the power to go down mid-flash!
- Make sure that the BIOS flash process is explained clearly by the accompanying documentation. Ambiguities can lead to all sorts of problems.
- Keep your hands (and feet) off the keyboard and mouse while the update is in progress - they system has enough to do without having to deal with you hassling it!
- If in doubt, DON'T!
If things go wrong ...
It is possible for a bad BIOS update to turn a PC into a pile of junk. Many modern PCs have special features that allow the effects of a bad BIOS update to the rolled back (it's a good idea to have a read of the motherboard manual before you begin and familiarize yourself with the process). These features vary from board to board so I can't give you any specifics on them, but when things go wrong they can be lifesavers.
If you have an older board that doesn't have any BIOS recovery features, don't switch off the power to the PC if the update goes wrong. Instead, try it again. If that doesn't work, go back and check that you are using the right update for the board you have.
I won't lie to you though, there is a chance that you can junk your motherboard. If that does happen then you either need to send the board back to the manufacturer to be revitalized, of you need to find a new board.
Final words ...
Remember, if you don't need to update your BIOS, or don't know why you are doing it, you probably don't need to do the update in the first place.