In most cases, nothing will go wrong at all, but it's important to know that there's an associated risk and not to treat the process too lightly.
It's good to have a spare copy of all important files from your PC before you start.
Sometimes this will be done automatically as part of the updating process, but if it requires you to do it manually, be sure not to skip this step.
The easiest way is to look in the user manual of your mainboard.
You will need a ISO image as well, and Free DOS is the most appropriate for installing BIOS updates.
Once you have the bootable drive, In the unlikely event you have to update from a floppy, a bootable disk can be created by entering format a: /s into the command prompt (in DOS).
Head to the motherboard or laptop manufacturer's website and look for a support link.
However this isn't always the case, even for new motherboards or laptops, and it's possible that you will have to create a bootable CD or USB drive and copy the files to that.
Additionally, the full model name –such as P5E3 Deluxe – is usually found somewhere on the board itself.
It’s important to get the full name as there are ususally subtly different versions.
Identifying your BIOS version is easy: hold down the Windows key R to bring up the Run command prompt and type in msinfo32.
In the System Information window which appears, select System summary on the left and look for the entry BIOS Version/Date on the right.