The BIOS is pretty much the settings that your motherboard holds such as overclocking. But if you haven't tampered with it previously it may not be that. Did you install all the drivers? including the motherboard ones, i always forget about those!
I had a similar problem after my BIOS settings fucked up and the computer just didn't wanna work. Try all other things you can think of but if that doesn't work look into reseting your BIOS. (This is if you have changed anything in it ofcourse)
This happened and im stupidly impressed with myself! (First few mins are the only bits that matter TBH)
Note: The music wasn't even edited in, was just playing a playlist whilst it happened, and the song changed at the perfect moment.
Feel free to share any of your Dayz moments.