try this, power down the PC, clear the cmos (with the jumper across the pins, then remove the round battery which powers the cmos, leave pc for about twenty minutes, put battery back into pc and boot up.
when it gives the warning, enter the bios and change the DATE & TIME ONLY. reboot and see what happens.
if you still have problems and if you can get into the bios, maybe try the default setting (safe setting) to get the pc up and running, rather than trying to go for the best settings.
dont know the asus bios too well so cant help much.
try looking in the bios for
whatever you can find that looks like it might help. if you actually get the pc to boot, then try changing things ONE thing at once.
if you are still stuck, please come back with the full error message so we can have a look.