Please help!

[Confusedconstantly]

Im new to pc havin built my first one 3 month ago all has been fine until today when i tryied to run a new game (a way out) where after the loading menu the game would blackscreen but run in the background. I alt tab out and read somewhere to make it work i need to change my resolution, i cany rember what resolution i changed to but it wasnt supported and had a constant black screen with no image so o figred there must be something i can do in the bios to which i found pressing f2 or del like prompted did nothing after abit more reading belibed taking the cmos battery was the answer to getting into the bios now the current situation im in is cannot boot into bios and met with a american megatrends message stating to "enter settings to recover bios setting, press f1 to run setup' which doesnt nothing nor does any other button any help would be massivly aprichiated