Welcome to the forums.
There are two things working against you.
1 - the bios is not going to allow you to do much of anything, it's "locked down"
2 - it's an emachine.
PC makers don't want you to be able to overclock or upgrade easily, else you won't buy another, faster machine later on or you might damage the PC and RMA it back to them damaged for replacement/repair under the warranty.
I'm afraid there are a lot of people such as yourself that come to these forums and discover that their e-compaq-packard-dell machines are non-tweakable.