I've recently decided that I want to try and utilize my two graphics cards so that I can have a dual monitor setup. Unfortunately Windows only seems to notice my most recent graphics card installation - and so I've been told that I should look into my BIOS and try to enable two graphics cards.

I could not find this setting anywhere in my M2N68-AM Plus v0210 BIOS. After some further research I figured that I should perhaps upgrade my BIOS, so I searched and managed to download the latest version (v1804) as a ROM file. However I am having difficulty figuring out how to install it.

I've tried using the Asus EZFlash feature built into my BIOS, but when trying to load up a variety of different ROMs that are for my motherboard/BIOS I get the error:

Boot block in file is not valid!

I'm not totally sure what I should do to fix this, so I'm looking into other methods of upgrading my BIOS - however I can't really find any solutions that seem to work. Asus Update is for 32-bit only, AFUDOS doesn't appear to work on my Windows 7 64-bit system (I think it's supposed to run in DOS or something - but that just sounds confusing since I know nothing about DOS).

Could anybody help me with this?