Your Bios is the setup on your motherbord. To access the bios you have to press a function key (repeatedly) when you first turn on your computer. This is usually F2 although it could be any of them, even the escape key. If you have the manual it will tell you which one without having to try them all. Once into the Bios tab through each of the tabs until you see in one of the lists the Legacy USB, then enable it.(it will tell you how to do it on the screen) Restart your computer and hopefully you will have use of your Keyboard and Mouse. If you are struggling and find it difficult, try to borrow a PS2 Keyboard and Mouse and you will be able to install with them.( your USB Keyboard will then work after your install). If you have to use PS2 make sure it is plugged in before you start your computer. Good Luck Keep us posted.