I have a Asus Maximus IV Gene and could not get the igpu to work right so I turned it off in the bios ,when I turned it off it gave me the option of changing memory size from 64mb to 512mb what I would like to know is why does it give me a option to ...

Hi I have a Maximus IV Gene and a few weeks ago I changed video drivers and as the ATI drivers were being uninstalled the screen went black, now I have replaced enough drivers over the years so I knew I had to reboot at the end of the uninstall.The p...