Hello,
A few months ago I bought a M5A 78L-M USB3 motherboard for the computer I was building. I have finished building it, when I start it up I get the American Megatrends Inc screen. Soon it tells me to press F8 to get to the BIOS Boot up screen, if I do so, a change happens ont he creen saying that it has been selected but nothing happens. Afterwards more messages are formed and it tells me my CMOS date/time i snot set. I have changed the battery but stil get this. I later discovered if I pressed Alt+shift+Delete I get to a BIOs screen, upon doing it I have a few options such as F8 for the selection screen to allow me to choose where to boot from. I need to boot from disc. The problem I face is when I press F8 nothign happens. No matter what I press nothing happens and it soon goes back the the American Megatrends Inc screen. I have tried reinstalling the BIOS from a memory stik but still it does the same. Any ideas?

Are you using a usb keyboard? Does the motherboard have a ps2 keyboard socket? If so, you may need a ps2 keyboard to get into the bios.

When it asks for you to set the date+time, did you do so? Some BIOS's won't let you go further until the clock is set. Also, some BIOS's require you to boot into the BIOS to change the boot device. My Intel motherboard works that way.

I have changed the time. It was not giving me the option to do so before just shutting down. I did some fiddling about and got it working. Everything is up and running and I am in love with my new computer :D

Great! If at anytime you can't access the bios, just set your jumper to reset position and set the bios settings! :)