Hi all, ever since I bought my Dell Dimension C521 I have not been able to enter the boot menu or the system setup when I start the computer. My usb keyboard does not start until the windows vista login screen. So I can hit f2 all thru the start up and it still not activate the keyboard until the login screen. I do not have a ps2 slot. How can I get to those menus??? Im not shure what kind of MOBO I have.