Demystifying BIOS updates - The DOs and DO NOTs

Summary: 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.

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Note: Even though the BIOS is now legacy and has been superseded by EFI, there's no sign of the BIOS disappearing any time soon.

The BIOS

Demystifying BIOS updatesBIOS 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.

Topics: Software, Hardware

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14 comments
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  • Some of this advice is overly-cautious ...

    [i]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!)[/i]

    Even older motherboards can get a little extra life out of them with a new BIOS. Definitely do some research on what you're going to gain, but BIOS updates don't necessarily have to be an "only if something's broken" situation anymore.

    [i]"... never, ever, update the BIOS from within Windows."[/i]

    This, to me, is kind of old-school advice. I've found newer Windows-based BIOS updaters to be about as stable and more friendly to use than DOS-based updaters. YMMV, and I certainly haven't worked with utilities from every mobo manufacturer or OEM, but this is not such a hard and fast rule anymore.

    One extra word of advice -- at the very least, the Windows utilities generally allow you to make a backup of your current BIOS to the same type of file that your new BIOS download will be in. Make this copy and include it on your boot disk in case you have to rollback.
    RationalGuy
    • Disagree a bit

      "but BIOS updates don't necessarily have to be an 'only if something's broken' situation anymore."

      Well, maybe newer motherboards are better at flashing the BIOS and recovering from incomplete flashes, but I've been burned enough times to know that older motherboards you don't want to mess with unless you really need it. Definitely check the motherboard manual to see if it supports rolling back bad updates. If you can't find rollback support, don't take a chance.

      I think some caution is definitely warranted, since a bad update can really make a system useless.

      Newer system might be better, but older systems should really not be touched unless absolutely necessary.
      CobraA1
  • Yuck

    Working with 1970s technology really sucks.
    frgough
    • Oh come on. Be a macho man and dig into this funkytown bios gig!

      :D
      HypnoToad
  • Fatal attraction

    I never can resist the fatal attraction of a new BIOS version, even if I don't need it.....

    As a result, the motherboard of my previous PC was killed. In a flash. And in the past, I've toyed with hacked unofficial BIOS versions as well. Living dangerously. :-)

    However, there is one thing I've never done: flashing a BIOS from within Windows. Something which even I never dared. Well, it will never happen as yet, because two years ago I made a full switch to Linux.

    One addition to your fine article: Intel provides iso's for boot CD's for flashing it's motherboard BIOS'es. Which is very much preferable to using boot floppies: a floppy disk is in itself highly vulnerable and unreliable.

    Greeting, Pjotr.
    pjotr123
  • I agree with you with one important caveat:

    Do NOT run ANYTHING else in Windows while you're doing a BIOS update.

    And I mean NOTHING, ESPECIALLY YOUR VIRUS SCANNER AND ANY HIDDEN WINDOWS PROCESSES. Run MSCONFIG and turn off everything that would appear automatically on the task bar.

    (I had one client who tried to run a BIOS update while she was running Outlook.)
    OButterball
    • My bad, the foregoing was meant as a response to dkawalec , above. (NT)

      :(
      OButterball
  • My advice

    My advice: [b]Only update it if you really need it.[/b] It's very risky and you can end up with a dead PC if it's not done properly. Frankly, 99.9% of the time it's not worth the risk.

    Only do it if you know it's going to resolve some stability issues: If your system isn't crashing, leave it alone.

    And definitely make sure you're hooked up to a UPS when you do it! If you have to go to somebody else's house or borrow somebody else's UPS, do it. This is a one time event, and it's well worth the hassle to ensure your system does not go down while performing the update. [b]Any interruption of the update can make the system totally useless![/b] That can't be emphasized enough.

    If you have the money and it's still being sold, buying a replacement motherboard with the new BIOS is often a better option.
    CobraA1
  • Don't update your BIOS if...

    You don't know what the BIOS update is supposed to do.

    If you don't know and can't find out what the BIOS update will do (a very unlikely situation) and can afford to trash an experimental system, be my guest.

    I've only updated on system's BIOS from within Windows. An MSI motherboard with the company sourced update in order to resolve a problem with my microphone input. I made a BIOS recovery disk prior to running the update. Then shut every unnecessary process down and removed all unnecessary peripheral devices, including unplugging the network cable. Monitor, CPU, mouse, and keyboard are the only items necessary to run the BIOS update. Once started, don't touch it until it's through running.

    Didn't have any problems, other than seeing stars from holding my breath.
    Dr_Zinj
  • Asus Updates Through Windows Work Fine

    I've never had a problem updating the bios on Asus motherboards using a BIOS update file I've downloaded from Asus and the Asus Update utility in Windows. I've probably run this over 20 times on 6 computers without fail. Perhaps you've run into problems without other manufacturers, but so far, Asus' Update utility has worked just fine within Windows.
    dl@...
  • What about DELL?

    What about being mutliple bios revs behind? i.e. bios is A02, and the current one from Dell is A16.

    Something had to cause Dell to release 14 revisons over the years.

    Do you leave it at A02 until you have a strange issue, or do you keep the bios resonably
    current?

    It is a tossup...
    smwells@...
    • about DELL

      I've updated a number (~12) of Dell P4s and haven't had a problem yet. Some of the updates caused WinXP to install much better drivers than those installed with the earlier BIOS.
      CaptOska
  • RE: Demystifying BIOS updates - The DOs and DO NOTs

    I have flashed numerous BIOS and have built upwards of 400 machines. I have on about a half dozen occasions screwed it up too. Fortunately I have lots of new and used spare parts and frequently a couple of the same model MBs. Recently I flashed my wife's ECS board machine and did it with the correct model number BIOS but incorrect BIOS for the board's revision number. Dead board! However, having a spare board and having a socketed BIOS chip, I fired up the other good board with the chip lightly socketed, pulled the chip out with the board running, plugged in the bad chip, and flashed. It worked but I have done this 3 or 4 times previously. Not for the feint hearted but I was desperate! Most work perfectly but you can't be 100% certain til its' done.
    rkoenn
  • Bad Bios Burn

    One thing you might want to consider is to make the acquaintence of a PC shop that has a EE/PROM burner. If the bios chip is in a socket, take the mobo and the image file to the shop. they can pop out the chip, burn it, and put it back into the mobo.
    CaptOska