if you have keyboard control in BIOS, see if you can get into windows safe mode by hitting F8 a bunch of times before you lose keyboard control. See if you get keyboard function in safe mode, then remove your old graphics drivers if you can.
I assume you are using a USB mouse/keyboard. if you can not get it to work try the old ps/2 type connector if your motherboard will still support it.
-if using USB, remove any extra USB devices from the USB host (mainly anything that is charging like a IPAD, also, make sure you are connected to a standard USB port )