I own a Biostar TA75A+ mobo and have no problem accessing the bios in the past but I recently added some more RAM, I now have 12gb but it says only 2.99 are usuable (I have a 4gb and a 8gb stick), so I wanted to go into bios but when the bios screen comes up I have held down the DELETE key, I have taped it rapidly and it wont come up it just goes straight to the windows 8 loading screen?