Flashing BIOS - ROM file does not match existing BIOS size

Kevin someone in the other thread asked what size PSU you have now I am not sure what you have hooked up but one way you can check what size PSU you need (for starters) because what you have looks to be a tad on the small size at 450W - eXtreme Power Supply Calculator - The only power supply calculator trusted by PSU manufacturers and computer enthusiasts

Just enter in as much as you can and the readout should give you roughly what size you need with some margin of error. Now if the result is close to the 450W PSU you have?? then under heavy load it might well be trying to draw more than what is available. Remember the stated output is the ideal and in reality some power is lost with the internal workings of the PSU circuitry/s.
Personally I use a PSU that has at least 25% more than I possibly need and just because it says for example 650W on the label doesn't mean that it is producing 650W continuously the device only puts out what is being asked of it. That is to say if your machine's components are idling at a draw of 200W then that is all a 650W PSU will put out - it is sort of working on a linear scale for want of a better way of putting it. :)

Just so you know, a BIOS update is not a driver update. Two very different things. A BIOS update is a firmware update. Do it wrong and you could render your motherboard totally useless. The Firmware/BIOS is what starts it up, boots it up. If it won't POST because of a bad flash its just a big paper weight. Be sure you downloaded the correct BIOS for your motherboard. They are motherboard specific and can be even revision specific. A motherboard may be revised during production and have a silently different revision number than the original production run.