When you upgrade a system without replacing the motherboard, it is important to consider the BIOS version. Some system features such as support for faster or more recent processors, large hard disks, high-speed transfer modes, and AGP are BIOS-dependent. Upgrading BIOS-dependent features often requires the user to upgrade the BIOS, as well. Fortunately, recent systems use a flash BIOS, which can be upgraded simply by downloading a later version of the BIOS to replace the existing BIOS.
Don't Take Chances
Be very careful when upgrading the system BIOS. Make absolutely sure that the BIOS upgrade patch you apply is exactly the one required for the current BIOS. Applying the wrong BIOS update may result in an unusable motherboard that may need to be returned to the factory for repair.
Updating the BIOS
Depending on the motherboard manufacturer and model the method to update the BIOS may vary. Some motherboards can be updated by copying the updated BIOS file to a floppy disk or CD and then booting from it. Other motherboards use a DOS-based "flasher" program that runs from a floppy disk and installs the BIOS file when it executes. Intel motherboards support Intel Express BIOS Update, which allows updating the BIOS from within Windows simply by double-clicking an executable file. (Fortunately, Intel provides floppy disk-based BIOS updates that Linux or other non-Windows operating systems users can use to update their BIOSs.)
Updating the BIOS can be intimidating, but BIOS updates usually complete successfully if you do everything by the numbers. But if you accidentally apply the wrong patch or if the update process fails through no error of your own, the PC can end up non-bootable. If this happens, there may not be an easy way to recover. Depending on the BIOS manufacturer and model, you may be able to use one of the following methods to recover from a failed BIOS update:
- A few motherboards have dual BIOS chips. If a BIOS was corrupted during an update, you can boot the system from the other BIOS and reflash the corrupted BIOS.
- Intel motherboards have a jumper that configures the motherboard for one of three modes of operation: Normal, BIOS Update, and Recovery. To update the BIOS, you must set that jumper to update mode. If the update fails, the jumper can be recovered to the Recovery position. The Recovery position gives the motherboard enough smarts to access the floppy drive and to load a BIOS update from the floppy drive.
Belt And Suspenders
A failed BIOS update can have dire results, so you should never update a BIOS without first connecting the system to an uninterruptible power supply (UPS) while doing the update. The one time we violated that rule, sure enough, the lights flickered about five seconds after we started the update. Hoping against hope that the PC hadn't crashed (this update was one where the screen stays blank until the update is complete), we sat staring at the blank screen for another half hour before we admitted to ourselves that we'd probably just killed the motherboard. With our fingers crossed, we shut down the system and rebooted it, but, as expected, it was deader than King Tut. Unless your luck is better than ours, always use an uninterruptible power supply when updating a BIOS.