How do I enter my Bios??

Try using cpuid, a free download, to id your motherboard chipset and ram specs. You can also try the "del" key to enter the bios at the post screen. Dell bios adjustments are limited; I would not change them except for the boot order is it's an option. If your system is stable, leave the bios alone. Dell boards aren't designed for overclockers or tweakers. If you want to play with your bios settings, I suggest you build your own.

Ok here is my system,
4gbs of ddr2 ram (I added 2gbs)

Amd athlon 64x2 6000 3.00 GHz (I upgraded the prosseser and installed a scythe shrunken CPU cooler)

Upgraded from the stock 280watt to a Ultra LSP 650watt ps

EVGA 9800gt

Windows Vista home premium 32bit SP 2

MOBO: ??? I think it is this…
DMI Baseboard
vendor Dell Inc
model 0FP406
revision A03

Chipset: nVidia

Like I said, I can’t even use the keyboard at the post screen (it won’t start working until the login screen)

It says in the top right hand corner, “F2 for system setup” and “F12 for boot menu”

I want to increase my CPU fan speed and the program “speed fan” does not recognize any of my fans, voltages, etc.

So, what do I do?